List of Articles
NMFS Cooperative Shark
Basking Shark Tagging and
Telemetry in the UK
Registers of Tagging -
Sarah Fowler 1"
International Game Fish
Tag and Release Data 0
Circulation in Europe
Sawfishes Considered for Illustration @ R Williams 1993
CITES advice sought
Marine Fish Added to List of World's Most Threatened Animals
Status of the Kitefin Shark
Leonard J.V. Compagno and Sid F. Cook
Population Genetics: an Accessory to Tagging Studies
WANTED: Whale Shark Rhyncodon typus Samples
Tracking Sharks by Videocamera Crittercam: the Video Parasite
lan K. Fergusson 0
Satellite Tracking Blue Sharks
Manta Tagging Starts in the Maldives
Catch/Tag-and-Release: the Conservation Option for Recreational Shark
Robert E. Hueter
Release Mortality Studies in Massachusetts
Gregory Skomal and Bradford Chase
Archival Tagging of Sharks in Australia
Data Storage Tags: Individual Behaviour-based Approaches to Migration
Nick Dulvy and Julian Metcalfe
Sharks and Man
Tagging at the Natal Sharks Board
Elasmobranch Biodiversity and Conservation in Sabah
Spiny Dogfish Landings Crash in British Columbia
Sid F. Cook
Philippine Whale Shark and Manta Ray Fisheries
Obituary: Mike Holden, OBE
0 -II- -fT~^^^^
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NMFS Cooperative Shark Tagging Program
Nancy Kohler, National Marine Fisheries Service, USA
A juvenile tiger shark Galeocerdo cuvier, tagged by
scientists in the Bahamas, about to be released. Photo: -
The National Marine Fisheries Service (NMFS) Cooperative Shark Tagging Program
(CSTP) is part of continuing research directed to the study of the biology of large
Atlantic sharks. The CSTP was initiated in 1962 with an initial group of less than 100
volunteers. The Program has expanded in subsequent years and currently includes
over 6,500 volunteers distributed along the Atlantic and Gulf coast of North America,
and Europe. The tagging methods used in the CSTP have been essentially unchanged
during the past 30 years. The two principal tags that are in use are a fin tag (Jumbo
Rototag) and a dart tag ("M" tag). The rototag is a two piece, plastic cattle ear tag
which is inserted through the first dorsal fin. These tags were primarily used by NMFS
biologists on small sharks during the first few years of the CSTP. As the Program
expanded to include thousands of volunteer fishermen, the dart tag was developed to *-e
be easily and safely applied to sharks in the water. The "M" tag is composed of a
stainless steel dart head, monofilament line, and a plexiglas capsule containing a vinyl
plastic legend with return instructions printed in English, Spanish, French, Japanese
and Norwegian. These dart tags, in use since 1965, are implanted in the back
musculature near the base of the first dorsal fin. More recently, a Hallprint tag has been
used on a limited basis for use on small sharks in the nursery areas.
Numbered tags are sent to volunteer participants on self-addressed return post cards
for recording tagging information (date, location, gear, size and sex of shark), along
with a tagging needle, tagging instructions, an Anglers Guide to Sharks of the
Northeastern United States, and a current Shark Tagger newsletter. This newsletter is
an annual summary of the previous year's tag and recapture data and biological
studies on sharks which is sent to all participants in the CSTP. Tagging studies have
been mostly single release events in which recoveries are made opportunistically by
recreational and commercial fishermen. When a previously tagged shark is re-caught,
information similar to that obtained at tagging is requested from the recapturer. Initially,
a five dollar reward was sent as an incentive for returning tags; since 1988, a hat with
an embroidered logo has been used.
Between 1962 and 1995, more than 128,000 sharks of 40 species have been tagged
and more than 6,000 sharks of 32 species have been recaptured, as a result of the
CSTP. Eighty-six per cent of the tags are represented by eight species: blue shark
Prionace glauca, sandbar shark Carcharhinus plumbeus, dusky shark C. obscurus,
tiger shark Galeocerdo cuvier, shortfin mako Isurus oxyrinchus, blacktip shark C.
limbatus, scalloped hammerhead Sphyrna lewini and Atlantic sharpnose shark
Rhizoprionodon terrraenovae. The number of sharks tagged varies from two for the
smalleye hammerhead Sphyrna tudes to 70,303 for the blue shark.
Numbers of recaptures by species range from one for the Greenland shark Somniosus
microcephalus to 3,098 for the blue shark. Eighty-six per cent of the recaptures are
made up of seven species: blue shark, sandbar shark, tigershark, shortfin mako, lemon
shark Negaprion brevirostris, dusky shark, and nurse shark Ginglymostomatum
cirratum. The rate of recapture ranges from 1.4% for the Atlantic sharpnose shark to
10.6% for the nurse shark.
Anglers using rod and reel accomplish the majority of the tagging for all species
combined. Biologists, NMFS fisheries observers, and commercial fishermen using
primarily longlines, handlines, and nets (gill, trawl) account for the remainder.
Conversely, commercial fishermen using longlines and net gear, and rod and reel
anglers are responsible for the majority of the recaptures.
A juvenile tiger shark Galeocerdo cuvier, tagged by scientists in the Bahamas, about to
be released. Photo: Jeremy Stafford-Deitsch.
Distances travelled for the 32 species ranged from no movement to 3,740 nautical
miles (nmi). In total, one species, the blue shark, travelled distances over 3,000 nmi,
three species travelled distances between 2,000 and 3,000 nmi (shortfin mako, dusky
and sandbar shark), eight species between 1,000 and 2,000 nmi (tiger, bignose C.
altimus, galapagos C. galapagensis, bigeye thresher Alopias superciliosus, night C.
signatus, oceanic whitetip C. longimanus, blacktip, and porbeagle shark Lamna nasus)
and seven species travelled distances between 500 and 1,000 nmi (scalloped
hammerhead, spinner C. brevipinna, longfin mako I. paucus, silky C. falciformis, sand
tiger Odontaspis taurus, Atlantic sharpnose and white shark Carcharodon carcharias).
The longest time at liberty for any shark in the CSTP is 27.8 years. Overall, one
species of shark, the sandbar shark, has been at liberty over 20 years, three species
have been at liberty between 10 and 20 years (dusky, night and tiger shark), and 13
have been at liberty between 5 and 10 years (scalloped hammerhead, shortfin mako,
blacknose C. acronotus, bignose, porbeagle, blue, thresher A. vulpinus, nurse, Atlantic
sharpnose, blacktip, silky, bull C. leucas, and bigeye thresher shark).
Data from tagging programmes, such as the NMFS CSTP, provide valuable
information on migration. The need for international cooperation is underscored by the
fact that many shark species have wide ranging distributions, frequently traverse
national boundaries, and are exploited by multinational fisheries. The CSTP is also an
important means to increase our biological understanding of sharks and to obtain
information for rational resource management. The tagging of sharks (and other
aquatic animals) provides information on stock identity, movements and migration
(including rates and routes), abundance, age and growth (including verification/
validation of age-determination methods), mortality, and behaviour.
For more information on the NMFS Cooperative Shark Tagging Program, please
0 -II- t
Apex Predator Investigation
28 Tarzwell Drive
Narragansett, RI 02882 USA
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Basking shark tagging and telemetry in the UK
A number of research groups based in the UK are hoping to undertake tagging studies
of basking sharks this year. Various techniques are planned, including the use of
satellite, radio and visual tags. Study locations range from the south-west of England,
to the Isle of Man (where visual tagging studies have now been under way for several
years) and the west coast of Scotland.
The Marine Conservation Society (MCS) is also continuing its sightings scheme, with
members of public, fishermen and yachtsmen being encouraged to record all sightings
of basking sharks. The data recorded are put on the MCS database, which already
holds several thousand records from previous years.
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Registers of tagging programmes
Sarah Fowler, Shark Specialist Group
While collating just the small amount of information on tagging programmes which
appears in this issue of Shark News, it became apparent that there are a very large
number and varied range of tagging programmes in operation, with several new
initiatives starting up in different countries this year alone.
The question immediately arose: how are these coordinated so that the data which is
obtained from tag returns is not lost? Is there a central register of tag and release
programmes, which ensures that tag returns eventually make their way back to the
appropriate organisation and are matched with the original release data? No doubt
these are very obvious questions to all those who have been actively involved in
tagging programmes for some time, but this information appears not to be generally *
available to individuals who are setting up new tagging initiatives for the first time.
My enquiries have resulted in information being provided on just two such registers.
International Game Fish Association Register
The IGFA reportedly publish a world-wide list of fish tagging programmes. This list is
updated annually and appears in their World Game Fish Yearbook. Unfortunately,
details of programmes contained in this register and when it is updated had not been
obtained by the time Shark News went to print. However, if we obtain more information,
we will publish this in the next issue.
The address of the International Game Fish Association is: 1301 East Atlantic Blvd.,
Pompono Beach, FL 33060, USA.
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Tag and release data circulation in Europe
An international system has been set up within Europe for the exchange of both c
release information and recaptured fish data. In theory, all organizations and
individuals contributing towards tagging programmes should send details of the fish
they have tagged (e.g. release date and position, species, length, sex, condition and
liveliness when released) to their national coordinating body (usually a marine
laboratory). For England and Wales, the Fisheries Research Laboratory, Lowestoft, of
the Ministry of Agriculture, Fisheries and Food, not only keeps the national release list,
but also summarises and copies it to all MAFF port offices around the UK and to similar -.
establishments in other European nations. Each national office then pays a reward for
the recapture of each tag returned within that country (plus market value of the fish if
the body is also surrendered), and ensures that the recapture information is forwarded
to its country of origin. This reciprocal arrangement, whereby the cost is born by the
country of recapture rather than origin, minimises administrative costs and balances
out in the long run. However, each country's tags must be identifiable for the system to
work! The Fisheries Laboratory at Lowestoft has quite a few untraceable tags which
were recovered from elasmobranchs tagged in unattributable tagging programmes!
Contact Martin Vince, Ministry of Agriculture, Fisheries and Food, Directorate of
Fisheries Research, Fisheries Laboratory, Pakefield Road, Lowestoft, Suffolk NR33
OHT, UK, for more information on tagging programmes in England and Wales.
It is obviously essential for all tagging programmes to be fully integrated in a major
national or international tagging scheme to ensure that the return rate of recaptured
tags is maximised. New taggers should take note and make appropriate arrangements.
At the very least, it is essential that each country's tags have an identifying national
prefix code! Researchers setting up new tagging projects should ensure that they
obtain details of the appropriate national tag prefix and use it.
-iSearch Ie r
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Sawfishes considered for CITES advice sought
As we have reported in previous issues of Shark News, there is concern among many
Shark Specialist Group members over the decline of sawfishes (Family Pristidae)
throughout the world. Sawfish are exploited for their rostral saws, meat, oil, fins, and
skins. International trade in sawfish products may be contributing to the continued
decline of sawfish species. For example, it has been recently reported that Chinese
distributors may be supplying souvenir shops and biological supply companies in the
US with rostra from Anoxypristis cuspidata. Therefore, listing sawfish species on
CITES (Convention on International Trade in Endangered Species) may be a valuable -
conservation tool for monitoring and/or controlling international trade in these already
threatened species. Species that are threatened with extinction and that are, or may
be, affected by trade are listed on Appendix
I, whereas species that may become
threatened if such trade is not properly
controlled are listed on Appendix II. Trade in
Appendix I species is prohibited; trade in
1 n species listed on Appendix II must be
controlled through an export permit issued by
the exporting country after showing that the
export will not be detrimental to the species'
survival in the wild.
In March 1996, the US government
published a Federal Register notice soliciting
recommendations for species to be
Largetooth sawfish. Artist: Sid F. Cook.
Ss ih. Arti C considered for listing on Appendix I or II of
1991 M.I. etinger. All rights CITES at the Tenth CITES Conference of the
Parties in June 1997 (COP10). A proposal to
list all species of sawfishes on Appendix I was submitted to the US Fish and Wildlife
Service (FWS) by SSG members Sid Cook and Madeline Oetinger. The US is currently
reviewing this proposal and will ask for public comment on it in a Federal Register
notice to be issued near the end of August. The US government will then decide
whether or not to sponsor a listing proposal for sawfishes at COP10 based on
feedback from the scientific and conservation communities and the public at large. *1
Other CITES Parties may also be sought as sponsors for the sawfish proposal.
One of the roles of the Specialist Groups is to advise IUCN on CITES listing proposals
and resolutions. The Shark Specialist Group must decide whether to endorse the
sawfish listing proposal should the US or other CITES Party decide to sponsor it for
COP10. Shark Group members will be discussing the sawfish proposal and other
potential CITES listing proposals and resolutions at the SSG meeting on 3 August, at
the World Fisheries Congress in Brisbane.
We invite all SSG members to review the sawfish listing proposal and advise the SSG
on its merits. If you would like to receive a copy of the proposal by email or post,
please contact Merry Camhi (email@example.com or fax: (516) 581-5268). Any
thoughts concerning sharks and CITES should be forwarded to Merry Camhi or Sarah
Fowler as soon as possible.
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Marine fish added to list of world's most threatened
Elodie Hudson, Zoological Society of London, UK
The conservation of marine species, especially fish, has long taken second place to
terrestrial conservation concerns. Little is known about the health of the marine
environment, and whether the risk of extinction is a real threat to fish species, many of
which are a major source of food to the world's growing human population.
A first attempt to assess threats to species in the seas was made by 31 leading
scientists at a workshop held by the Zoological Society of London (ZSL), the World
Wide Fund for Nature (WWF) and the World Conservation Union (IUCN) in April this
year. Using the new IUCN categories and criteria for assessing threat, they evaluated
148 species of marine fish, ranging from seahorses and coral reef fish, to sharks and
tunas. The aim of the meeting was twofold. First to assess the threat status of the
candidate marine species, and second to assess the applicability of the new IUCN
categories to marine fish.
The threat classification system of the IUCN recently underwent a major revision. The
new system is intended to be flexible, objective and systematic. It operates on a
system of five criteria which reflect the biological and environmental factors which can
cause extinction. Only one of these five criteria needs to be met for a species to qualify
for threatened status, and quantitative thresholds are given for each criterion to define
the category of threat (Critically Endangered, Endangered, or Vulnerable) the species
will fall into. There are also categories for species at low risk, not evaluated, or for
which data is insufficient (Data Deficient), so effectively all animals can be placed
somewhere in the system.
The workshop participants evaluated a candidate list of 148 species of marine fish and
found 118 of them to be threatened. Of these, ten were classified in the highest threat
category, Critically Endangered. Among the threatened fishes were several species of
shark (including the great white), tuna, groupers, cod, haddock, swordfish, halibut,
many coral reef fish, and seahorses. The major threat to these fishes is chronic
overfishing, be it for food, shark fin soup, aquaria, the Chinese medicine trade, the live * *
food trade or for sport. Habitat destruction is also a problem, especially for fishes living
in coastal habitats such as coral reefs or mangrove swamps. These fish will appear
alongside other threatened animals in the IUCN Red List of Threatened Animals, which
will be published in October at the World Conservation Congress in Montreal. Their
presence on the list will hopefully elevate the importance of protecting the marine
environment in the minds of decision makers and conservationists alike. The list has no
specific legal force, but is used by governments and other organizations as a guide to
setting priorities for conservation.
From the evaluation process emerged guidelines to help future evaluators to use the
IUCN categories these continue to be developed. In most cases, the criteria were felt
to be appropriate for assessing the threat status of marine fish. In some cases they
were not, and these are the focus of continuing work. The overriding problem with
applying the criteria is that scientists are hampered by a lack of knowledge of marine
ecosystems and their component species. Hopefully this stimulating and interactive
workshop will act as a catalyst for further efforts in the current climate of growing
concern over the oceans and the valuable resources they contain.
(The above was originally commissioned for Living Oceans News.)
Elodie Hudson, Institute of Zoology, Zoological Society of
London, Regent's Park, London, NW1 4RY, UK.
Tel: 44 (0)171 449 6690, fax: 44 (0)171 483 2237,
SS u IF d
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Status of the kitefin shark Dalatias licha (Bonnaterre, 1788)
Compiled by Leonard J.V. Compagno and Sid F. Cook *
Adult female .;ifn shark Dalatias licha 1
SE. Sicilian Channel, Mediterranean Sea,
0 lan Fergusson, l q Q
The kitefin shark is a monotypic species in the genus Dalatias, order Squaliformes. The
family Dalatiidae [formerly part of Family Squalidae] includes the tail-light, pygmy, cigar
and cookie-cutter sharks.
A relatively common, but unevenly distributed, deeper-water dogfish found on continental
and insular shelves and slopes in warm-temperate and tropical areas, from 37 m down to
1800 m depth in the north and central Atlantic, western Indian Ocean, and western and
central Pacific Ocean. It is an epibenthic species, but often ranges well-off the bottom.
Ecology and reproduction
The kitefin shark is an adept and powerful deep-sea predator feeding on a broad variety .i* e
of bony fishes and elasmobranchs. It also consumes cephalopods, crustaceans, and
annelid worms. Harvest records from Mediterranean fisheries indicate that this is not a
schooling species, but primarily a solitary shark.
An ovoviviparous species, giving birth to 10-16 pups per litter. Size at birth is about 30
cm. Maximum size of adult males is at least 1.2 m, and adult females at least 1.6 m. *
Little, if anything, is known about growth, age at maturity, or life span in the wild.
This shark has long been exploited commercially. Among products derived from it were
or are: denticle-intact skin for use as "shagreen" for polishing in cabinet and jewelry
making; fishmeal; leather (considered excellent for the manufacture of "boroso", a
durable, almost armor-like denticle-intact polished leather in Spain); human consumption
(eastern Atlantic and Japan); and squalene oil (Portugal and Japan).
The Portuguese have developed a limited deep-water fishery that harvests several
hundred tons a year. This fishery appears to be extremely limited in its potential, with
rapid degradation of stocks noted when more than around 900 mt are taken in a fishing
season (J.G. Casey, personal communication).
Because of the generally great depth at which this species appears to spend most of its
time, historically it was taken primarily in deep-water directed fisheries efforts. However,
with recent trends in development of deep fishing gear (especially trawl gear) and the
increasing need for commercial fisheries to fish deeper in attempts to sustain harvest
levels, this species and other deep-sea elasmobranchs will undoubtedly come under
increased pressure in the future from new multi-species fisheries.
IUCN threatened species assessment
Vulnerable (Ald, A2d) throughout its range. This assessment of a 20% population
reduction world-wide within an estimated three generation period is based on rates of
stock and CPUE reduction from present and former directed fisheries (see Portuguese
example above) and the likely continuation or acceleration of this trend in future as deep
water fisheries effort increases.
Editor's note: The above is a greatly abbreviated version of the draft account supplied by
the compilors for the Shark Action Plan. The original, including many references, is
available from the Editor.
Ed Heist, Center for Biosystematics and Biodiversity, Texas A&M -
Many species of sharks span vast geographic ranges but may be divided into isolated
breeding populations. If conservation efforts are to succeed, these individual
populations need to be identified so that we can determine whether locally-depleted
regions can be replenished from other areas. One way to do this is to examine
movements of individual sharks through traditional tag and recapture. Another, more
recent, technique involves analysis of population genetics using polymorphic
characters. The purpose of this article is to discuss the relationship between traditional
tagging and genetic studies, and to demonstrate how both kinds of research can add to
our understanding of shark populations.
While tagging studies detect movements of individuals within a single lifetime, genetic
studies track movements of genes over many generations. When two populations
become isolated reproductively, gene frequencies change over generations through
random genetic drift. Ultimately isolated populations become fixed for alternate alleles;
for many generations however only frequency differences will exist. Reproduction
between individuals from different regions results in gene flow, homogenising gene
frequencies between regions. By examining frequencies of polymorphic genes from
different geographic regions we can estimate the amount of gene flow that has taken
place over past generations.
Both techniques, tagging and population genetics, have strengths and weaknesses.
Genetic homogeneity between regions is not proof that separate fishery stocks do not
exist: populations may not have been isolated long enough for differences in allele
frequencies to develop; or an exchange of only a few individuals per generation is
sufficient to maintain the same alleles in different populations. Tagging studies may
thus reveal significant stock structure in the absence of any genetic structure. On the
other hand, genetic studies may reveal details about reproductive life-histories of
organisms not detectable by tagging studies. Some marine organisms, sea turtles and
whales for example, have separate breeding populations that overlap during part of the kes
year. Studies in these organisms have revealed significant population structure despite not
the fact that individuals from separate breeding units intermingle. Many species of
sharks deliver their pups in coastal nursery areas distant from the locations where
adults are usually found. Genetic studies may tell us whether female sharks return to
the same nursery area from which they came, and therefore whether local depletion of
juvenile sharks in a coastal nursery area will have a long-term effect on future
generations of pups. *
Population genetic studies have been published on sandbar sharks in the US and on
the gummy shark, spot-tail shark, and Australian blacktip shark in Australia. Other
projects under way include studies on the great white and whale shark. Recently, John
Graves, Jack Musick and I published a paper on population genetics in the shortfin
mako (Heist et al. 1996). We examined mitochondrial DNA genotype frequencies in
makos from the North Atlantic, South Atlantic, North Pacific and South Pacific. We
found there was a highly significant difference in genotype frequency between the
North Atlantic and other samples, suggesting little or no exchange of makos between
the North Atlantic and other oceans. This finding is also consistent with the tagging
data of Casey et al. (1992) that shows long-distance movement of tagged makos within
the North Atlantic, but no recaptures south of the equator or in other oceans. Both
population genetics and tagging can thus provide important information for the
conservation of shark populations.
Casey, J.G., and Kohler, N.E. 1992. Tagging studies on the shortfin mako shark
( Isurus oxyrinchus) in the western North Atlantic. Aust. J. Mar. Freshwater Res. 43: 45
Heist, E.J., Musick, J.A., and Graves, J.E. 1996. Genetic population structure of the
shortfin mako ( Isurus oxyrinchus) inferred from restriction fragment length
polymorphism analysis of mitochondrial DNA. Can. J. Fish. Aquat. Sci. 53: 583-588.
Ed Heist, Center for Biosystematics and Biodiversity, Texas A&M
University, USA. Email: firstname.lastname@example.org
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Whale shark Rhyncodon typus samples
Researchers at the Hubbs-Sea World Research Institute and the University of Florida
(USA) are conducting a global genetic survey of whale sharks Rhyncodon typus. They
need help to collect tissue samples from throughout this species' range.
Strandings, incidental catches, fishery products and nondestructive tissue samples are
all acceptable sources of material. Just a gram or two of tissue is required from each
specimen. Samples can be stored in saturated salt (NaCI) solution without refrigeration
and shipped by air mail. Previously frozen samples are acceptable.
For more information please contact:
Dr Brent Stewart,
Hubbs-Sea World Research Institute,
1700 South Shores Road,
San Diego, CA 92109 USA.
Email: email@example.com, fax: 619-226-3944;
or Dr Brian Bowen,
BEECS Genetic Analysis Core,
12085 Research Drive,
University of Florida, Alachua, FL 23615 USA.
Email: firstname.lastname@example.org, fax: 904-462-0875.
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Tracking sharks by videocamera Crittercam: the video
lan K. Fergusson, European Shark Research Bureau, UK
'Traditional' methods of telemetry, developed from simple tagging programmes, have
provided shark biologists with a plethora of spatio-temporal, behavioral and
physiological data about their subjects that have greatly advanced our understanding
of these fishes. However, while telemetry provides important information on the short
and medium term movements and behaviour of elasmobranchs, it fails to offer the -
researcher a real-time view of the study animal's second-by-second behaviour. Thanks
to the expanding science of manufacturing compact, miniaturised video technology, the -
detailed recording of such behavioral information is now becoming attainable.
One of the most remarkable
developments is the Crittercam,
brainchild of National Geographic
Television's Greg Marshall. This
camera is designed for parasitic L
attachment to a shark's (or other
large aquatic animal's) dorsum by
means of a corrodable or other
temporary link causing minimal harm
to the host's skin. For sharks,
standard stainless-steel Floy darts
have been used which are detached
from the camera either by a
magnesium wire (which severs in
saltwater after a pre-determined White shark towing Crittercam. Photo: lan K.
soak-time) or by using an ultrasonic Fergusson, 1993.
trigger mechanism. The camera, towed smoothly behind the shark at about the level of
the first dorsal fin, has a forward-looking wide angle view and records all activity in real
time from the moment of attachment to release (about two hours or full tape duration).
As the Crittercam also contains ultrasonic telemetry gear, the shark can be tracked,
followed by boat and its precise movements mapped by researchers using a 6
hydrophone, thus allowing the time-coded video to be continually cross-referenced with
its precise location.
Precise details of the Crittercam's construction are confidential, but a brief description
can be provided. The camera housing is custom-made from metal and synthetics and
its contents carefully configured to provide hydrodynamic stability, perfect balance and
minimal drag. It is compact and torpedo-shaped, containing an adapted HI-8 Sony
camcorder chassis and recorder section powered by integral battery. The optically
corrected semi-wide angle lens films through a toughened, hemispherical port on the
front of Crittercam and is focused on infinity. The rear of the 'hull' contains ultrasonic
telemetry equipment and a surfacing radio pinger to enable retrieval of the camera
following release from the host. A more extensive array of data-logging recorders,
including those sampling sea temperature, depth and swimming speed, can be
attached to the hull.
The writer viewed Greg Marshall's use of Crittercam on white sharks off South Africa in
1993-1994 (Fergusson 1995), during the filming of a co-funded BBC Natural History
Unit/National Geographic TV film, "Great White Shark" (Prog. No. NBS-50-604Y, first
transmitted in the US and UK in March and April 1995). Successful deployments of the
Crittercam system were accomplished at Dyer Island (near Gansbaai) and Struisbaai,
Cape Province. All cameras were recovered and a number of useful video tape records
collected. Full results are unpublished, but several interesting events were recorded,
including cruising and patrolling behaviour between surface and seabed; short-
duration, opportunistic pursuits of fish and small sharks; and interactions with other
white sharks and cape fur seals Arctocephalus pusillus pusillus. Topside tracking
offered useful information on the spatial habits of white sharks.
Greg Marshall has revised attachment and retrieval methods. This work will greatly
advance the simplicity and durability of field-use for both commercial cinematography
Fergusson, I.K. 1995. Great White Lies. BBC Wildlife Magazine, 13 (4): 32-37. April
Satellite tracking blue sharks
Andy Kingman (formerly Woods Hole Oceanographic Institution) *
In 1993 Frank Carey (Woods Hole Oceanographic Institution) built four ARGOS
satellite tracking devices for a study on blue sharks Prionace glauca. In 1994 three of
them were deployed on adult male blue sharks off Cape Hatteras, North Carolina,
USA. They have provided information on depth, water temperature, swimming speed
and location. One (shark #1) transmitted only once, on the first day; another (shark #2)
transmitted 93 times over the course of 17 days; and shark #3 approxim-ately 300. -
times over the course of 36 days.
The transmitters are modifications of a design developed by
the Sea Mammal Research Unit (SMRU), Cambridge, UK.
Two aluminium pressure tubes house a transmitter, a *
microprocessor, two lithium "D" cell batteries and depth,
temperature and speed recording equipment. The tubes are
cast in a urethane saddle, which is attached directly to the
shark's back. A rotor for measuring swimming speed, a wet/
dry transmission switch and the antenna are mounted on an
eighteen inch (45 cm) mast. Transmissions are initiated
when the mast breaks the surface. At the latitude of the
study area (approx. 350N), satellite coverage is close to 110
minutes/ day, during which period approximately 5% of the
Satellite transmitter on
the back of a blue possible total number of transmissions were successfully
shark. Photo: F.G. completed.
Carey. Data received included temperatures ranging from 8.4 to
22.20C, and depths ranging from the surface to over 500 m. During the 17 days it was
tracked, shark #2 covered more than 400 nautical miles, and shark #3 covered more
than 1,100 nautical miles over 36 days. Both of these study animals received a
significant boost in speed from the Gulf Stream; mileages were higher than 30 miles/
day during periods when swimming was highly directional and parallel to the current. At i
speeds like this, the sharks could easily accomplish a trans-Atlantic migration over the
course of a few months.
Capsule tag studies have provided
point-to-point data demonstrating
that blue sharks will cross oceans,
but these studies provide no
information on course and behaviour
between tagging and recapture.
Sonic tracking experiments have
provided detailed information on
behaviour over a short time, but are
impractical for periods of more than
one week. Satellite tracking offers a
means of collecting detailed data
over an extended period of time.
After ironing out some of the
technical difficulties experienced in
this trial, and with newer, more
compact transmitters already
available, tracking durations of
several months are easily within
reach. Unfortunately, Dr Carey's
death in December 1994 has
precluded the continuation of this
study, but the stage has been set for
more satellite tracking of fish.
A paper on this study is currently in
preparation, possibly for Marine
Ecology Progress Series, authors: F.
G. Carey, A. Kingman, N. Kohler, J.
Bisagni and C. Hunter or M. Fedak.
W- -ly' N
__ .4-_ .g ^T'A-. .. -
Track taken by transmitting blue sharks overlain
on false colour satellite image showing surface
water temperature. Graphic: J. Bisagni.
Andy Kingman, 2253 Buttonwood Road, Berwyn, PA 19312, USA. Email: lamna@aol.
i Se F s a S I. *r
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Manta tagging starts in the Maldives
Manta rays Manta birostris are common in Maldivian waters, where they are a major
attraction for tourist divers. Mantas are known to undertake seasonal migrations from
side to side of the Maldivian atoll chain, in synchrony with the changing monsoons.
They also undertake daily migrations between cleaning and feeding areas, apparently
in phase with the tides. Although this broad picture is known, the details of the
migrations are not.
A proposal to carry out a tagging study of manta movements was made to the Marine
Research Section of the Maldivian Ministry of Fisheries by an Austrian dive base
operator, Mr Norbert Schmidt, in late 1995. A joint proposal was formulated and
tagging trials have now started. Tags used are 'Floy' spaghetti tags of about 40 cm
length, each individually coded with four colour segments. The tags can be identified
underwater by divers, so the movements of individual manta rays can be monitored
over long time periods.
Initial tagging trials were carried out in February 1996 (during the north-east monsoon
season) in Ari Atoll on the west of Maldives by Norbert Schmidt and Herwarth
Voightmann, another dive base operator. It was found that the tag head had to be
slightly modified, but once that was done one manta was successfully tagged by a
diver in the water. No resighting has been reported to date. Subsequent trips to tag
mantas in the same area were unsuccessful, either because no mantas were present,
or because other divers were in the water with the mantas at the same time. An article
on the initial tagging trial has appeared in a popular German diving magazine
(TAUCHEN, Hamburg, May 1996).
Further trials are to be carried out on the eastern side of the country, near Male, in
September 1996 (during the south-west monsoon season). If they are successful,
larger scale tagging will be carried out and extensive publicity will be given to the
programme in order to maximise reporting of resightings. An interesting feature of this
tagging programme is that it is being funded entirely by a diving base operator,
because of his interest in manta rays.
R. Charles Anderson, Marine Research Section, Ministry of Fisheries and Agriculture,
Male, Republic of Maldives.
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Catch/tag-and-release: the conservation option for -
recreational shark fishermen
Dr Robert E. Hueter, Center for Shark Research, Mote Marine
More and more, sport fishermen around the world are choosing to practice catch-and-
release of sharks, often tagging their catch for science. What has turned anglers away
from the old attitudes of catch-and- kill of sharks, leading to the demise of many of the
traditional shark kill tournaments? At least three factors have been involved. First, the
conservation movement in sport fishing has slowly changed the ethic in recreational
shark fisheries by educating fishermen about the value of all marine resources, *
including sharks. Second, the proliferation of shark-tagging programmes has given
anglers a satisfying alternative to killing or just releasing their catches. And third, and
perhaps the most profound reason, the alarming depletion of large sharks in many
coastal regions has sharply reduced the number of sharks available to sport fishermen.
As depletions have been documented, a number of jurisdictions have instituted
management measures, setting restrictions on shark landings by recreational
fishermen. So whether it is by choice or by rule, anglers are electing for live release of
a greater proportion of their shark catch.
This attitude shift has benefited tagging programmes around the world. Prominent .
among these has been the US National Marine Fisheries Service's Cooperative Shark
Tagging Program (see page 1), which began in 1963 and currently involves about
6,000 volunteer fishermen (Casey et al. 1995). Although there are many pluses to the
growing interest in tagging by fishermen, there are minuses as well, and both should
be considered when assessing the value of angler shark-tagging programmes.
Obviously, catch-and-release, with or without tagging, can decrease recreational
fishing mortality on shark stocks, a desirable objective in this era of shark
overexploitation. The embracing of catch-and-release and tagging by recreational
shark fishermen can be a powerful conservation tool. This is because the inherent
conservation message is disseminated among the fishing community and out to 0 6
resource managers and the public. The results are an impression on management that
the recreational sector is 'doing its part', increased pressure on the commercial sector
to follow suit, and a more enlightened public concerning the resource value of sharks.
An example of this effect has been seen in Florida with the annual Gulf Coast Shark
Census, a 100% catch-and-release sport tournament for shark research coordinated
by Mote Marine Laboratory. Over the eight years of this tournament, nearly 1,000
anglers many of them formerly shark killers have caught, collected data on, and
released over 4,500 sharks, 530 of them with tags applied by Mote biologists. Media
coverage of this tournament has magnified its message, helping to accelerate the fall
of shark kill tournaments in Florida (Hueter 1991a, b). -
Proper tagging of the shark catch can provide basic biological information on shark
migration, age and growth, natural mortality, behaviour and habitats, as well as applied
information for shark fishery managers (Casey and Taniuchi 1990). Volunteer taggers
can cover a much broader geographic range, at a greatly reduced cost, than can
fishery-independent scientific tagging programmes. The over 113,000 sharks tagged in
the NMFS programme from 1963 to 1993 (Casey et al. 1995), for example, would no
doubt be far less if it had depended solely on federally funded boats and personnel.
This participation has important educational value in that fishermen become active
partners in the search for scientific truth, benefiting all involved.
Despite these benefits, there are pitfalls to angler catch/tag-and-release of sharks. The
most obvious is post-release mortality. As sport fishermen like to say, a shark has a
much better chance of surviving if it is released than if it is lying on the boat's deck. But
if the stress of capture is mortally damaging the sharks, catch-and-release is not
accomplishing what the fishermen may think it is. There have been a number of studies
on post-release mortality of hook-and-line-caught fish (see pages 8-9). In general,
sharks caught-and-released on recreational tackle have a much better chance of
surviving than on most commercial gear. However, if the allure of tagging is attracting
significant numbers of new shark anglers, rather than simply altering the behaviour of
those already in the fishery, then post-release mortality becomes more important.
Closely related, but subtly different, is tagging mortality and other, sublethal effects of
tagging on the sharks. Fishermen, as well as biologists, require training to apply tags
properly. Tags improperly applied or placed in the wrong types of sharks can fall out,
kill the animals, or affect their growth. Bad tagging technique or poor choice of tag type
then, can be far worse for the shark than simple release. These problems can also
affect the scientific objectives of tagging: tag retention can go down, affecting
quantitative measures of population parameters; tags can affect sharks' behaviour,
altering normal migratory patterns; and tags can stunt growth, seriously biasing
estimates of age and growth in these species.
Scientists can address these issues by conducting rigorous studies of tag design and
technique before deploying tags in either a fishery-independent or cooperative angler
programme. The specific size and style of tag can be matched to the shark being
caught-and-released. For example, young or small adult sharks cannot accommodate
tags designed for larger, tougher animals (Manire and Gruber 1991). To reduce
mortality from large tags, the juvenile shark-tagging programme at Mote Marine
Laboratory uses biologists to tag the sharks with appropriate tags and concentrates on
recreational fishermen to recapture them.
Finally, the quality of the data shark species, sex, size etc. is lower in a cooperative
angler programme. This can be accounted for in data analysis, but it can never be
corrected. In other words, the data collected in an angler tagging programme must
always be weighted differently than the data collected by the biologists themselves. Bui
as with the other pitfalls, this drawback can be outweighed by the many practical and
conservation-oriented benefits of tagging. Properly implemented, the tagging of sharks
by sport fishermen provides a wealth of new information and immeasurably adds to
global efforts to conserve shark species.
Casey, J.G., Kohler, N.E., Stillwell, C.E., Turner, P.A., Briggs, R., Pratt, H.W., and
Natanson, L.J. 1995. A summary of shark tag-recapture data from the NMFS
Cooperative Shark Tagging Program (1963- 1993). Amer. Fish. Soc. 125th annual
meeting abstracts: 126.
Casey, J.G. and Taniuchi, T. 1990. Recommendations for future shark tagging
programs. In: Elasmobranchs as Living Resources: Advances in the Biology, Ecology,
Systematics, and the Status of the Fisheries. Eds. H.L. Pratt Jr., S.H. Gruber, and T.
0 -II- t
Taniuchi.) Pp. 511-512. US Dept. Comm., NOAA Tech. Rep. NMFS 90.
Hueter, R.E. 1991a. The rise and fall of recreational "kill" tournaments for sharks in
Florida: historical trends, research potential, and the conservation movement. J. Aust.
Mar. and Fresh. Res., Sharks Down Under Conference meeting abstracts, Sydney,
Hueter, R.E. 1991b. Survey of the Florida recreational shark fishery utilising shark
tournament and selected longline data. Mote Marine Laboratory Tech. Rep. 232A
(Final report to Florida DNR, Project 6627): 94 pp.
Manire, C.A. and S.H. Gruber. 1991. The effect of M-type dart tags on field growth of
juvenile lemon sharks. Trans. of the Amer. Fish. Soc. 120(6): 776-780.
Search Fis Selections...
Release mortality studies in Massachusetts
Gregory Skomal and Bradford Chase, Massachusetts Division of *
Marine Fisheries, Vineyard Haven, Massachusetts
Extensive recreational fisheries for tunas, billfish and sharks occur off the coast of New
England from June through October each year. Those species commonly targeted by
offshore anglers include: bluefin tuna Thunnus thynnus, yellowfin tuna T. albacares,
albacore tuna T. alalunga, bigeye tuna T. obesus, skipjack tuna Katsuwonus pelamis,
Atlantic bonito Sarda sarda, false albacore Euthynnus alletteratus, white marlin
Tetrapterus albidus, blue marlin Makaira nigricans, blue shark Prionace glauca, and
mako shark Isurus oxyrinchus. .
In recent years, there has been an increasing trend in the release of angled gamefish
by the offshore recreational fishing sector. Catch and effort data compiled by the *
Massachusetts Division of Marine Fisheries from 60 big game fishing tournaments held
in Massachusetts from 1987 to 1995 show that 5,821 large pelagics were caught by
tournament anglers during 29,345.5 boat hours of fishing effort. Overall, 75.7% of
these fish were released and 21.4% were tagged before release. Notably, 78.9%
(8.4%) of the bluefin tuna, 96.7% (74.5%) of the white marlin, and 92.0% (20.8%) of
the blue sharks were released (tagged).
While some of this is due to the imposition of management measures such as
minimum sizes and bag limits designed to reduce mortality on immature fish, there
have also been changing attitudes among recreational anglers and tournament*
organizers. Cooperative tagging programmes have contributed greatly to the education
of fishermen relative to fish conservation and the importance of biological study. The
angler that tags and releases fish now feels a sense of contributing to causes that will
enhance the fishery. Discussions about numbers of fish tagged have slowly replaced
those about numbers of fish killed among the sport fishing community.
Little is known of the mortality associated with the release of pelagic gamefish.
Evidence from National Marine Fisheries Service (NMFS) Cooperative Tagging
Programs shows a higher recapture rate for sharks (4%) (N.E. Kohler, NMFS, NEFC,
pers. comm.) than billfish (1.1%) (Bayley and Prince 1994) and non-bluefin tunas li
(2.6%) (D. Rosenthal, NMFS, SEFC, pers. comm.). Although low recapture rates can
be attributed to tag shedding, emigration, stock size, natural mortality, and reporting
failure, mortality associated with angling stress cannot be discounted.
In general, fish react to the acute stress of capture, severe exercise, and handling with
more exaggerated disruptions to their physiology than those seen in higher vertebrates
(see reviews by Wood 1991 and Milligan 1996). Nearly all species of fish have a
substantial proportion of their myotomal muscle mass (80%-95%) as anaerobic white
swimming muscle which reflects an ability for high work output in short bursts (Driedzic
and Hochachka 1978). Angling practices cause increased anaerobic activity, muscular
fatigue, and time out of water, resulting in marked respiratory and metabolic changes
(Wood 1991; Ferguson and Tufts 1992).
Since fish blood comprises only 3%-6% of the body weight and white muscle over
30%, changes in muscle biochemistry will be reflected strongly by the composition of
the blood (Wells et al. 1986). Therefore, measuring the changes in various
haematological parameters relative to the degree of physical exhaustion can provide
useful indices of stress.
The objective of our ongoing study is to elucidate the physiological effects of angling-
induced stress on the survivor-ship of pelagic species commonly caught offshore of
New England. In contrast to previous studies, fish are captured, tagged, and released
utilising standard angling practices and equipment. Field-collected blood samples
provide a 'snapshot' of the physiological status of each animal taken. The response of
each blood constituent to varying levels of stress is quantified. While it is understood
that this study, like its predecessors, cannot overcome the difficulty of obtaining blood
from stress-free fish, we do attempt to measure sub-lethal and lethal disturbances due
to the effects of the various angling practices. Hypotheses on release mortality are
tested using acoustic telemetry.
To date, we have sampled 289 gamefish comprised of 12 species of sharks, tunas and
billfish. Due to sample size limitations, the bulk of our analyses have been confined to
bluefin tuna, yellowfin tuna and blue sharks. Preliminary findings show that these fish
exhibit fluctuations in blood pH and blood levels of hormones, electrolytes and
metabolites due to the fight associated with rod and reel angling. Each species was
found to have a different physiological response to angling. For example, the metabolic
by-product of anaerobic glycolysis is lactic acid. We found that blood lactate levels in
angling-stressed tunas were significantly higher than those in sharks and marlin.
Moreover, bluefin tuna possessed extremely high levels of blood lactate relative to
other species sampled. Since blood lactic acid readily dissociates into the lactate anion
and hydrogen protons, the amount of this metabolite in the blood contributes to the
acidity of the blood. By measuring the pH of the blood, we can determine the extent of
the acidosis. Extreme acidosis can cause more complex physiological disturbances
which may severely impede normal behaviour and ultimately compromise survivorship
(Wood et al. 1983).
For each species, changes in blood chemistry can be compared to several variables
which are associated with the fight such as tackle type, fight time, water temperature
and fish size. Most of the correlations we have conducted to date are associated with
fight time. The following gives a brief preliminary synopsis of what happens
physiologically to bluefin tuna, yellowfin tuna and blue sharks during the angling event.
This species exhibits
immediate drops in blood pH
due to the build-up of carbon
dioxide and metabolic by-
products in the blood. This
acidosis seems to drive the
pH to its lowest level in fish
that have been fought for 20
to 25 minutes.
The blood pH measurements
made on yellowfin tuna
fought on rod and reel are
much lower than those
reported as 'normal' by other ..
researchers for this species. Anglers may apply tags without bringing the shark into
Although the degree of the boat. This should help to reduce stress and improve
acidosis fluctuates greatly survivorship. Photo: H. Wes Pratt.
with fight time, lowest pH levels are reached after as little as 10 minutes of fighting.
The magnitude and nature of blood disturbances appear to be less dramatic in the
sharks when compared to the tunas. Blood gas measurements indicate that the blue
shark is not hampered by respiratory problems when fought on rod and reel; blood
oxygen levels remain relatively high. Blood pH does decrease slowly to a low at a fight
time of about 40 minutes. This can probably be attributed to the slow increase in
metabolic by-products like lactate. Nonetheless, pH levels remained appreciably higher
in this species relative to the tunas fought for similar durations.
Can these species recover from this physiological disturbance? Short and long term
recovery from the acute stress associated with exhaustive exercise was evaluated from
tag-recapture and ultrasonic tracking studies. Both methods allow for inferences on the
effects of tagging. We have tracked two blue sharks, three bluefin tuna, and one
yellowfin tuna after exposure to prolonged fights on rod and reel, blood sampling, and
tagging. Minimum tracking periods for these fish were eight hours, with the exception oi
one blue shark which was followed for four hours. All fish survived this tracking and
appeared to recover from the physiological effects of exhaustive exercise.
Tag recaptures of two blue sharks and one yellowfin tuna that were previously blood-
sampled, by the study provided long term evidence that these fish were not
physiologically compromised by the angling experience or the tagging.
It is very important to emphasise the scope of this study. We are specifically attempting
to quantify and assess the physiological effects of rod and reel angling. In doing so, we
encounter varying degrees of physical trauma as well. The rough handling of fish, the
use of gaffs, internal hook damage, poor tagging, and excessive time out of water can
cause irreparable damage to a fish which is released. Recovery may take days or
months if the fish survives. While some degree of physical trauma can be assessed in
this study, short term ultrasonic tracking may not be sufficient to measure the long term
effects of such trauma. Tag recaptures of our sampled fish do help to rectify this.
Physiological stress can be minimised by reducing fight and handling time. However,
physical trauma can only be reduced through the conscious efforts of anglers when
choosing to tag and release a fish. Hook design, handling methods, tagging tools, and
experience all play a major role in the proper tag and release of gamefish.
Photo: H. Wes Pratt.
The importance of tagging large pelagic species of sharks, tunas and marlin cannot be
over-emphasised. These are species of fish which cannot easily be maintained in
captivity for biological studies. What we know of their complex biology, we must derive
from dead specimens or from tagging studies. A single recapture can provide important
information on migration, distribution, age, growth, longevity and reproductive biology
without killing the fish. The recreational angler has been an integral component of our
tagging programmes for decades and has thus contributed to the pool of knowledge
that scientists now have to work with. Only through these efforts can scientists provide
a valid foundation on which wise measures of conservation and utilisation of these
species can be built.
Bayley, R.E., and Prince, E.D. 1994. A review of tag release and recapture files for
Istiophoridae from the Southeast Fisheries Center's Cooperative Gamefish Tagging
Program, 1954 to present. ICCAT, Coll. Vol. Sci. Pap. 41: 527-548.
Driedzic, W.R., and Hochachka, P.W. 1978. Metabolism in fish during exercise. In:
Hoar, W.S., and Randall, D.J. (eds.). Fish Physiology, Vol. VII, Locomotion. Pp. 503-
543, Academic Press, NY.
Ferguson, R.A., and Tufts, B.L. 1992. Physiological effects of brief air exposure in
exhaustively exercised rainbow trout ( Oncorhynchus mykiss): implications for 'catch
and release' fisheries. Can. J. Fish. Aquat. Sci. 49: 1157-1162.
Milligan, C.L. 1996. Metabolic recovery from exhaustive exercise in rainbow trout.
Comp. Biochem. Physiol. 113A(1): 51-60.
Wells, R.M.G., Mclntyre, R.H., Morgan, A.K., and Davie, P.S. 1986. Physiological
stress responses in big gamefish after capture: observations on plasma chemistry and
blood factors. Comp. Biochem. Physiol. 84A(3): 565-571.
Wood, C.M. 1991. Acid-base and ion balance, metabolism, and their interactions after
exhaustive exercise in fish. J. Exp. Biol. 160: 285-308.
Wood, C.M., Turner, J.D., and Graham, M.S. 1983. Why do fish die after severe
exercise? J. Fish Biol. 22(2): 189-201.
Gregory Skomal and Bradford Chase, Massachusetts Division of Marine Fisheries, P.
O. Box 68, Vineyard Haven, MA 02568- 0068, USA. Fax: + 1 508 693 4157. Email:
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Archival tagging of sharks in Australia
John Stevens, CSIRO Marine Laboratory, Tasmania, Australia
Archival tags developed by CSIRO and Zelcon Technic Ltd have been used
successfully on southern bluefin tuna to provide continuous records of long-distance
fish movements, diving and feeding behaviour. These mini computers weigh 25 g, have
1 megabyte of flash RAM and contain an accurate time clock and depth, temperature
and light sensors. Diel changes in light are used to calculate longitude and day length
is used to calculate latitude. The tags can log data at predetermined intervals for nine
years and store it for 20 years.
Whale shark. Photo: Jeremy Stafford-Deitsch.
We have recently received funds to use this technology on both school Galeorhinus
galeus and whale sharks Rhyncodon typus. School sharks are a target species in the
$15 million/year Southern Shark Fishery. CSIRO and The Victorian Fisheries Agency
(VFRI) play a major role in the assessment of school shark stocks and in researching
the biology and population dynamics of this species. School sharks spend much of
their time on the continental shelf where they are fished by demersal gillnets and
longlines. However, they also occur on the upper slope and at times extend into the
oceanic pelagic zone, with conventional tagging showing a number of trans-Tasman
migrations to New Zealand. Archival tagging will be used to provide information on their
swimming depth and longer-distance movements. A question of particular interests to
scientists and industry is whether pupping grounds for the whole stock are restricted to
Victoria and Tasmania. Archival tagging of pregnant females may provide the answer.
We (CSIRO and VFRI) have trialled different attachment methods and tag designs
using 'dummy' tags. Internal tags (as used on the tuna) are surgically implanted in the
body cavity; the light sensor being mounted on an external streamer. Two external fin-
mounted designs have been used; the rectangular shape of the standard tag and a
torpedo-shaped hydrodynamic version with low drag. Perhaps surprisingly, most
returns have been of the internal dummy design.
Snorkelling with whale sharks is an important ecotourist industry at Ningaloo Reef in
northern Western Australia. Aggregations of whale sharks appear each year in March
and April close to the coast, probably in response to increased productivity associated
with mass coral spawning. We have received a grant under the National Ecotourism
Program to use standard telemetry, archival tags and satellite tags to study the short
and long term movements of whale sharks at Ningaloo. Three years ago we
successfully tracked two sharks (one for 26 h) and obtained interesting data on their
swimming depth and diving behaviour. We also attached six archival tags and,
although we retrieved one from a shark after 24 hours, none have been seen
subsequently, However, at least some individuals are known to return each year
recognizedd from distinctive wounds or markings) so by choosing some of these sharks
we are hopeful of success with further tagging. Whale sharks have been successfully
tracked for several months using satellite tags by a group in California and we will also
try similar tags at Ningaloo. While archival tags can be used to obtain positional data
underwater (providing the fish does not go below 100-150 m, the depth of usable light
levels) satellite tags must be at the surface for transmission.
John Stevens, CSIRO Marine
Laboratory, GPO Box 1538,
Hobart, Tasmania 7001, Australia.
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-iSearch IeS r
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Data storage tags: individual behaviour-based
approaches to migration
Nick Dulvy and Julian Metcalfe, MAFF Fisheries Research, UK
Traditionally fish movements have been followed by mark-recapture methods or by
analysis of catch data (e.g. Pawson and Nichols 1994, Rousset 1990). The former type
of study can provide estimates of speed and direction of movement during different
seasons, as well as growth rates, mortality estimates, rates of stock interchange, yield,
and stock replacement values (e.g. Smith and Abramson 1990, Holden 1972).
The disadvantages of simple studies are that large numbers of fish must be tagged
(1,000+), recaptures should be followed for as many years as possible (2-15 years)
and the data quality depends on the level of cooperation by fishermen. More
problematic, the estimates of some of the above variables can be flawed. Mark-
recapture methods only indicate net movement; for instance in a recent study an
electronically tagged plaice showed a net movement of 80 km over 56 days, when in
actual fact the fish had travelled 800 km and was recaptured on its return migration.
The key problem with conventional tagging studies is that if any condition varies, e.g.
size- or age-selectivity of the fishery, fishing pressure or environmental change, then
the parameters of the population will change, necessitating a costly re-estimation of
New methods of following fish movements
The Fisheries Laboratory of the Ministry of Agriculture, Fisheries and Food at
Lowestoft, UK, have developed an electronic "Data Storage Tag" consisting of
pressure and temperature sensors and a 1 megabyte chip to store the data. The tag
can record data for over nine months and store this data for five years. When the tag is
returned by fishermen the data is extracted using an infrared link.
The tag records vertical movement of the fish, which can be translated into horizontal
movements using a hydrographic simulation model. The whole system is based on the
knowledge that many coastal benthic fish species rise into the water column to catch a
'tidal conveyer', a form of movement known as "Selective Tidal Stream Transport". It is
assumed that horizontal movement is a function of the period of time spent in the water *
column and the rate of tidal flow and the vector of tidal current which the fish uses.
Temperature profiles can be used to validate broad scale movements, as can the tidal
profiles when the fish is at rest on the bottom.
One hundred of these tags were put on plaice in 1993 and I have just put 100 tags on
the thornback ray Raja clavata in the Irish Sea. Preliminary results from the 20 returned
plaice tags have demonstrated surprising results (Mackenzie 1994). For the first time
we can follow the movements of individual fish in the wild for longer than a week or so.
Not only do these fish move ten times faster than previously thought, but a number of
distinct behaviour patterns have been identified from this study, including: *
vertical movement linked to the night time period only
vertical movement using both tides in the daily cycle
vertical movement using night tides in one direction only.
These vertical migrations have direct consequences for geographical movement.
Progress is currently being made towards determining the cues triggering these vertica
movements. Once this can be determined, then individual behaviour-based predictive
models can be constructed to simulate population movement and distribution. The
beauty of these data are that the individual cues to migrate are independent of fishing
or environmental shifts, therefore such models could be used to predict the spatial and
temporal effect of changes in fishing effort or habitat loss on fish populations
Relatively large numbers of electronic tags are required, as we are dependent on
returns from the fishery. Nonetheless, cost is comparable to if not cheaper than the
cost of large-scale conventional tagging studies. In the future it is hoped that this basic
form of tag will be modified to download data to passing aeroplanes or even satellites,
avoiding the problem of obtaining fishery returned tags.
Holden, M.J. 1972. The growth rates of R. brachyura, R. clavata and R. montagui as
determined by tagging data. J. Cons. int. Explor. Mer., 34: 161-168.
Mackenzie, D. 1994. In pursuit of plaice with chips. New Scientist, 6.
Rousset, J. 1990. Population structure of Thornback rays Raja clavata and their
movement in the Bay of Douarnenes. J. Mar. Biol. Ass. U.K., 70: 261-268.
Smith, S.E., and Abramson, N.J. (1990) Leopard shark Triakis semifasciata
distribution, mortality rate, yield, and stock replenishment estimates based on a tagging
study in San Francisco Bay. Fish. Bull., 88: 371-381.
Sutherland, W.J. 1996. From individual behaviour to population ecology. Oxford
University Press, Oxford, UK, p. 213.
Nick Dulvy 1 & 2 and Julian Metcalfe 2
1 School of Biological Sciences, University of East Anglia,
Norwich, Norfolk, NR4 7TJ, UK. Email: N.Dulvy@uea.ac.uk
2 Directorate of Fisheries Research, Ministry of Agriculture,
Fisheries and Food, Pakefield Road, Lowestoft, Suffolk, NR33
OHT, UK. Email: J.D.Metcalfe@dfr.maff.gov.uk
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Search Fishs Selections...
Sharks and Man
This workshop on shark management and
conservation will be held on 2nd August at the
Brisbane Convention and Exhibition Centre following '
the World Fisheries Congress. The three sessions
will cover Shark Control (including gear technology
and bycatch reduction, sonic "avoidance" beacons,
and electric field barriers), Shark Fisheries, and
Shark Conservation. Draft agendas for the latter two -
sessions are: Great white shark Carcharodon
carcharias. lan Fergusson,
Session 1. Management of Shark Fisheries 1994.
Information needs for management of shark
fisheries: Terry Walker (Convenor, Victorian Fisheries Research Institute). ^
Overview of world's shark fisheries: Ramon Bonfil.
Management of the artisanal shark fishery in the Gulf of Mexico: Fernando Marquez
and Leonardo Castillo.
Shark fisheries of Africa: Warwick Sauer.
Recreational and industrial shark fisheries of North America: Greg Cailliet, David Holts
and Pamela Mace.
Stock assessment and risk analysis for school shark off Southern Australia: Andre
Shark fishery management in Australia Keeping the fish in "fish 'n' chips": Trysh
General discussion & summing up.
Session 3. Shark Conservation
Organisers: John Stevens (CSIRO Fisheries, Australia), Merry Camhi (National
Audubon Society, USA) and Sarah Fowler (Nature Conservation Bureau, UK).
Introduction: John Stevens (CSIRO Fisheries, Australia).
Shark Specialist Group update action plan and report to CITES: Sarah Fowler (Nature *
Conservation Bureau, UK) and Merry Camhi (National Audubon Society, USA).
CITES and sharks summary of the CITES discussion paper by the US government: *
Andrea Oliver (NMFS, USA).
IUCN Red List applying the criteria to elasmobranchs: Elodie Hudson (Zoological
Society of London, UK).
Red List species assessments: Leonard Compagno (South African Museum).
International trade in sharks and shark products and implications for shark
management and conservation: Glenn Sant (TRAFFIC, Australia) and Debra Rose
Status of freshwater elasmobranchs: Leonard Compagno (South African Museum).
Protected species status white shark and grey nurse: Jon Presser (South Australian
Fisheries) and Dave Pollard (Fisheries Research Institute, Australia).
Options for international shark management: Sonja Fordham (Center for Marine
Elasmobranch bycatch monitoring: Ramon Bonfil (UBC, Canada).
Public attitude to shark control in Queensland results of a preliminary survey: Clyde
Wilde (Griffith University, Australia) or John Stevens (CSIRO Fisheries, Australia).
Summation: Shark conservation in the 21st Century: Michael Sutton (WWF, UK).
i S s S* Sl* Sr
Tagging at the Natal Sharks Board
Sabine Wintner, Natal Sharks Board, South Africa
The South African National Tagging Program is administered by the Oceanographic
Research Institute (ORI). Since its inception in 1984 it has recorded over 100,000 fish
(more than 350 species) tagged by 3,350 registered members. The Natal Sharks
Board (NSB) joined the programme in 1984, tagging free swimming raggedtooth
sharks Carcharias taurus. A pole sling is used by NSB snorkel divers to insert a yellow
"Hallprint" dart tag with stainless steel head and plastic streamer. By the end of 1995,
535 C. taurus had been tagged this way.
Of the annual average of 1,440 sharks caught in the nets, 15% are found alive, and
since 1978 the percentage of sharks released has increased steadily. This
development was a result of a gradual acceptance that many sharks caught pose little -
threat to swimmers and the increasing reluctance of those servicing the nets to kill live
sharks (Cliff and Dudley 1992). From 1978 to 1986, 462 netted sharks were marked
with NSB rototags. In 1987 the NSB changed to dart tags, and over 1,300 sharks from
14 species have been tagged to the end of 1995. The majority of these sharks were C.
taurus (over 670), followed by the tiger shark Galeocerdo cuvier (over 160) and dusky
shark Carcharhinus obscurus (over 100) and including 37 white sharks Carcharodon
carcharias. The NSB tags only one batoid species, the giant guitarfish Rhyncobatus
djeddensis; 330 have been marked. Average annual recapture rate of sharks is around
3% and for R. djeddensis over 6%. It is interesting to note that the recapture rate of C.
taurus tagged by divers, where there is no capture stress, is higher (5%) than that of C.
taurus tagged in the nets (3.4%).
Opportunistic tagging by NSB staff has increased the number of tagged C. carcharias
to over 50. Based on the combined ORI and NSB tagging databases, first estimates of
mortality and population size for C. carcharias on the South African coast were
calculated. The overall estimate was 1,279 sharks, F = 0.055 yr -1 and Z = 0.53 yr -1
(Cliff et al. in press). Based solely on the NSB tagging data, analysis commissioned by
the Board has estimated netting mortalities for various species: C. carcharias 0.07-0.15
yr -1 Carcharhinus leucas 0.02-0.03 yr -1 C. taurus 0.03-0.06 yr -1 and G. cuvier -
0.02-0.04 yr -1 given different scenarios of natural mortality, tag loss, tagging mortality
and under-reporting of recaptures.
In 1993 an additional programme was started, the Tetracycline Tagging Program. In
addition to being tagged the sharks are injected with the chemical oxytetracycline and
marked with an orange tag, instead of the conventional yellow one. The NSB offers a
'reward' of R 100 (23 US$) for the return of such a shark. Between 1993 and May 1996
nearly 400 sharks were injected, both in the nets and through opportunistic tagging.
The majority are again C. taurus (over 160), followed by G. cuvier (over 55) and C.
obscurus (over 35), and 18 C. carcharias have also been injected. Recapture rate to
date is 2%, with most sharks caught within the first month after tagging. The NSB is
continuing with this project and it is hoped that the future will see more valuable
recaptures of tetracyclined sharks.
Cliff, G., and Dudley, S.F.J. 1992. Protection against shark attack in South Africa.
Australian J. Marine and Freshwater Research, 43: 263-272.
Cliff, G., van der Elst, R.P., Govender, A., Whitthuhn, T.K., and Bullen, E.M. In press.
Tagging of white sharks provides first estimates of mortality and population size on the
South African Coast. In: Klimley, A.P. and Ainley, D.G. (eds.). Great White Sharks: the
Biology of Carcharodon carcharias. Academic Press, San Diego.
Sabine Wintner, Natal Sharks Board, Private Bag 2,
Umhlanga Rocks, 4320, South Africa. Tel: +27 31 561-1001,
fax: +27 31 561-3691, email: email@example.com
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Elasmobranch biodiversity and conservation in Sabah
The Shark Specialist Group's collaborative study with the Sabah Fisheries Department,
funded by the UK government's Darwin Initiative and announced in Shark News 4, has
now been underway for five months, with another year still to run until the final
workshop. The project commenced in January with the appointment of a Darwin
Project Officer, Mabel Manjaji, in the Fisheries Department and an initial field and
market survey by Fisheries Department staff and Shark Group members Leonard
Compagno, Sid Cook, Sarah Fowler and Frances Dipper.
Elasmobranchs in Sandakan market, Sabah. Photo: Sarah Fowler.
This initial brief visit determined that the chondrichthyan fauna of Sabah is more
diverse than formerly believed (the elasmobranchs of Borneo have not previously been
recorded in any detail). Of the 15 species of shark and 21 species of ray recorded
during the January visit, ten species and one genus ( Mustelus) were new records for rn ll
the whole of Borneo. The Mustelus sp. may be new to science. Stingrays were more
diverse, had a higher biomass than sharks in market surveys, and included some
poorly known species. Some sharks which are common and widespread in the region
are surprisingly under-represented. (Several additional species have since been
recorded.) Representative specimens are being purchased during market surveys and
preserved to provide a reference collection for future taxonomic research and as
Particularly interesting freshwater records were obtained in the form of photographs of
the giant freshwater stingray Himantura chaophraya, a fin set of the bull shark
Carcharhinus leucas and saws of Pristis microdon, all apparently from freshwater
reaches of the Kinabatangan River. There were also reports from fishermen of very
large guitar fish being caught in the same area, and the identity of other large river
stingrays described is still unknown. Unfortunately, flood conditions have persisted
since the start of the project and attempts to obtain specimens of these river
elasmobranchs have, so far, been unsuccessful. There have been no signs or reports
of the very rare Borneo river shark Glyphis sp.
The project has continued with a programme of market surveys, field surveys on the
Kinabatangan and Segama Rivers, and interviews with fishermen in river and estuarine
kampongs, occasionally also in collaboration with WWF-Malaysia. Assistance with
surveys and specimen identification has been provided by several SSG members,
some during holidays in Sabah (Gordon Yearsley, CSIRO, Australia and John
Denham, UK), others by correspondence.
Future work will include a survey of the socio-economic and cultural importance of
elasmobranchs to traditional subsistence fishing communities, to be started by Patty
Almada-Vilella in July. Frances Dipper will be developing a survey programme for
marine protected areas and an elasmobranch reporting and identification programme
for divers, the latter in collaboration with dive tour companies in Sabah. Any SSG
members interested in participating should contact Frances Dipper for more
information (7 Rutland Green, Hilton, Cambridgeshire, PE18 9NT, UK. fax (+44) (0)
1480 830507, email firstname.lastname@example.org). We may be able to arrange local
accommodation and transport for volunteers.
Sarah Fowler, Darwin Project Coordinator,
Nature Conservation Bureau, Newbury, UK.
Search Fis Selections...
Spiny dogfish landings crash in British Columbia
After 35 uninterrupted years of recording commercial spiny dogfish Squalus acanthias
landings in British Columbia, the Canadian Department of Fisheries and Oceans did
not report any commercial landings in 1994. This followed a 58% decline in reported
catches from 1990 to 1993. Landings in Washington and Oregon have increased
greatly since the end of the 1980s (when salmon stocks collapsed and local fishing
efforts were retargeted) and the small Californian fishery is stable. Nevertheless, there
has been an overall declining trend in total Pacific Northwest landings of this species
since 1990. If catch trends observed in other areas are followed, a rapid decline in total
spiny dogfish catches from Pacific North American waters may be anticipated in the
Sid Cook, Shark Specialist Group vice chair, Northeast Pacific region.
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Philippine whale shark and manta ray fisheries
A traditional, seasonal (April/May) whale shark fishery in Mindanao and the Visayas,
Philippines, was studied during a 15 day WWF field trip in 1996. Three hunting
communities were visited and several key fishermen interviewed. These individuals
know from experience exactly when and where they can expect to encounter their
prey, which range in length from 14 to 40 feet. They also reported that female sharks
occasionally contain egg-like structures with blood vessels, which they believe are
fertilised whale shark eggs.
Although local whale shark hunting practices are still very traditional, a large number of
fish are taken each season by just a small group of hunters. However, landings in 1996
were by far the lowest recorded in a hunting season (about 90 whale sharks in total
were taken by all hunting communities interviewed). Most hunters agreed that the
population and catches of whale sharks in their locality have been declining. One
hunting community with about eight hunting groups/boats (each boat has five
fishermen on board) reported their annual landings as 100 whale sharks during the*
1994 hunting season, 80 last year (1995) and about 40 this year (1996). While external
factors may (even partly) be responsible for this trend, it is possible that even this
traditional fishery is unsustainable.
Whale shark skins, fins, jaws and meat were seen being dried for market (it was not
possible to interview traders, who are concerned about the possibility that the whale *
shark hunt could be banned).
One manta ray with an approximately 12-foot wing span was seen being caught on one
of the islands. Fishermen on this single island had, by end of May, reportedly landed
about 1,000 rays since last December. Their flesh is also dried and traded.
Romy Trono, Director of Conservation,
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Obituary: Mike Holden, OBE
unexpectedly at the end of last year.
Mike's career had ranged from the West African Fisheries Research Institute, Nigeria,
to the UK Fisheries Laboratory in Lowestoft, culminating in the positions of principal
administrator and then Head of the Conservation Unit of the European Union's
Directorate General of Fisheries (DGXIV), retiring in 1990. He is possibly best known in
the international fisheries management and research community for dogfish research
and as author (in the early 1970s) of the first paper to draw attention to the potentially
unsustainable nature of long-term elasmobranch fisheries. However, he more recently
achieved notice in Europe for his post-retirement criticism of the TAC/ quota system
underpinning the Common Fisheries Policy. He argued in The Common Fisheries
Policy: Origin, Evaluation and Future (1994) for their replacement by a Brussels-run
licensing scheme which would provide the basis for a regime which would conserve
stocks and provide a profitable European industry.
Mike was always willing to provide valuable advice to the Shark Specialist Group; we
will miss his contributions greatly.
Search Fis Selections...
European Elasmobranch Society
There is good news to report on progress with the establishment of the proposed UK-
based European Elasmobranch Society (mentioned in a previous issue of Shark
News). The UK government nature conservation agencies, Scottish Natural Heritage,
English Nature and the Countryside Council for Wales, have just announced that they
will be providing a grant towards the initial costs of establishing this organisation. The
grant is smaller than that initially applied for, and only covers the period until end March
1997, rather than for the three years initially requested. However, we are confident that
this grant will enable the Society to be set up on a firm footing and enable us to raise
the additional funds necessary to match this grant and to support its activities in future
The Society will be launched at the Third European Shark and Ray Workshop (see
Anyone interested in membership details should write to: Sarah Fowler, The Nature
Conservation Bureau Limited, 36 Kingfisher Court, Hambridge Road, Newbury,
Berkshire, RG14 5SJ, UK. Fax: (44) (0)1635 550230, email:
email@example.com or firstname.lastname@example.org
Third European Shark and Ray Workshop
The third European Shark and Ray Workshop will be held at the National Sea Life
Centre, The Waters Edge, Brindley Place, Birmingham, on 25-27 October 1996.
Generous sponsorship from the UK Sea Life Centres means that, in addition to
interesting presentations from a number of UK and European speakers, participants
will hear talks from South Africa-based great white shark researchers Mark Marks and
Leonard Compagno, and John Morrissey from New York. The meeting promises to be
a very interesting and stimulating occasion.
If you would like more information on this meeting, please contact Gordon Croft, St *
Andrews Sea Life Centre, The Scores, St Andrews, Fife, KY16 9AS, UK. Fax: (+44) (0)
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Reproduction in the whale shark
Joung et al. (1995) have recently provided the first firm evidence of ovoviviparity in the
whale shark Rhyncodon typus, based on the dissection of a 7-8 m, 16,000 kg female
harpooned in the eastern waters of Taiwan in July 1995. Although previous literature
on the species has considered this type of reproductive strategy likely, the unexpected
aspect of this report is that about 300 embryos were revealed in the uteri. Several size
classes were present, suggesting a long breeding season. Most embryos were in
eggcases with yolk sac, but the largest (60-65 cm TL), presumably virtually full term,
were outside their eggcases. Some of these survived dissection and transfer to
aquaria. A report of these observations will also be presented at the New Orleans
American Elasmobranch Society Meeting in June 1996.
Joung, S.J., et. al. December 1995. Ovoviviparous whale shark. (Abstract of
Symposium paper, Tokyo, November 1995.) Report of the Japanese Society for
Elasmobranch Studies, 32, p.32.
Sawfish in the Mekong River
Shark Specialist Group member Tyson Roberts has drawn the editor's attention to
reports of sawfish in a 1993-1994 study of fisheries in southern Laos and north-eastern
Cambodia. Roberts and Warren (1994) note that sawfish (likely Pristis microdon and/or
P.clavata) caused considerable damage to gillnets and were occasionally caught as
recently as ten years ago just below the Lee Pee Waterfalls, Laos. One fisherman used
to see two or three of up to 10 kg in weight in February-March each year, presumably
following other migratory fish. Sawfish are now absent or very rare in the Great Lake of
Tonle Sap; the most recent known capture was 40 years ago. One Pristis was reported
landed at Ban Wernkam towards the end of 1993. Overall, the 1993/94 season was the
worst ever experienced by local fishermen, representative of a long-term basinwide
decline of Mekong fisheries, where gillnets are intensively used.
Roberts, T.R., and Warren, T.J. 1994. Observation on fishes and fisheries in southern
Laos and northeastern Cambodia, October 1993- February 1994. Nat. Hist. Bull. Siam
Soc. 42: 87-115.
Proposals for protection of sharks in Australia
The Australian Nature Conservation Agency has recently received a nomination for
protection of the white shark Carcharodon carcharias and the grey nurse shark
Carcharias taurus under the Endangered Species Protection Act. The grey nurse is
already protected in New South Wales, and the white shark protected in Tasmanian
waters and proposed for protection in South Australia, but listing under the Endangered
Species Protection Act would have the effect of protecting these species throughout
commonwealth waters. The federal government will also be required to consult states
and territories to develop and provide funds for national recovery plans for the species.
Sharks were noted as being potentially vulnerable in Australia's first State of the
Marine Environment report, released last year. The whale shark has recently received
protection in Western Australia.
Sharks highlighted in UK biodiversity report
The basking shark Cetorhinus maximus, tope Galeorhinus galeus, porbeagle Lamna
nasus and blue shark Prionace glauca have all been listed in the recently published UK
Steering Group Biodiversity Report Meeting the Rio Challenge. They appear on a long
list of some 1,250 species which are considered to be of conservation concern
(however, this is not considered to be a comprehensive listing). The report notes that
monitoring of these species is important in establishing a review of the health of
biodiversity in the UK, and should take place within five years.
The Marine Stewardship Council initiative
A major new initiative to halt the serious decline in global fish stocks was announced in
February by WWF International and Unilever Plc/ NV, one of the world's largest buyers
of frozen fish. They have agreed to create a Marine Stewardship Council (MSC)
following a wide-ranging consultation of all those involved with fisheries (from scientists
to regulators and environmentalists).
The MSC will be a wholly-independent body, setting out the broad principles of
sustainable fishing and laying down specific standards for individual fisheries. Products
made from fish caught in accordance with these standards will receive an MSC 'on-
pack' logo. This will allow consumers to select fish products that come from a source
certified as sustainable. Not only should this approach enable declining commercial
stocks to recover, with associated benefits for the marine environment, but it should
also help coastal communities dependent on fishing to avoid economic and social
The aim is for the MSC to adopt a similar approach to that which has successfully
promoted sustainable forestry; uniting the efforts of industry and the consumer to
promote market-led incentives for sustainable fishing. This approach seems more likely
to succeed than the repeatedly unsuccessful political efforts to tackle the problem of
declining fish stocks (e.g. by setting catch quotas and other regulations).
Conservation of chondrichthyans in the Maldives
1995 was an important year for shark and ray conservation in the Maldives, with a
number of new regulations coming into effect.
Whale sharks Rhincodon typus have been protected under the Fisheries Law which
prevents the catch of all types of bodu mas (a local term for true whales and other
large 'fish' including whale sharks). However, this term is ambiguous; some consider it
refers to true whales only. A couple of whale sharks were reportedly caught in 1994 for
their liver oil and/or fins, both of which commodities are of very low value in this
species. Whale sharks are recognized as a significant attraction for tourist divers. The
Ministry of Fisheries and Agriculture announced a specific regulation in June 1995,
banning all fishing for whale sharks, to reinforce the existing Law.
Rays, particularly manta rays (Mobulidae) and stingrays (Dasyatididae) are a major
attraction for tourist divers in the Maldives. There is a small traditional and sustainable
catch for rays for their skins (used on drums), oil and shark bait. However, any
increase in fishing effort to support an export fishery would likely prove non-
sustainable, damaging both traditional users and the tourism sector. To forestall and
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avoid such problems, the Fisheries Ministry banned export of rays from June 1995, anc
of ray skins from 1 January 1996.
On World Environment Day (5 June) 1995, the Ministry of Planning Human Resources
and Environment declared 15 top diving sites as Marine Protected Areas. Nine of these
are or were famous for their sharks, but there have over the years been a number of
incidences of fishermen catching sharks at these sites. Since a grey reef shark
Carcharhinus amblyrhynchos may be worth up to 1,000 times more alive as a source
of diving revenue than dead on a fishing boat, it makes sense to protect sharks within
Although these regulations provide significant protection for some chondrichthyan
fishes in the Maldives, there is a need for further action. For example, reef sharks are
not confined to particular reefs and, in the Maldives at least, do show some seasonal
migratory behaviour associated with the changing monsoons. Therefore, protecting
particular dive sites will not give these sharks complete protection. Plans are therefore
being considered to protect more dive sites as well as much larger reef areas where
tourism development is concentrated.
R. Charles Anderson and Maizan Hassan Maniku, Marine
Research Section, Ministry of Fisheries and Agriculture, Male,
Republic of Maldives.
Please send us the complete
citations and, if possible, abstracts of
any new papers or reports which you
have published or produced, and
which you feel may be of interest to .
other readers. We will endeavour to
provide details in future issues.
Reports do not have to be formally "-..-
published indeed those with a Sid Cook 1989.
restricted distribution which will not
make their way into standard citation lists are often of particular interest, since they
may not otherwise come to our attention.
The following are useful sources of information on elasmobranch or other marine
animal tagging programmes and techniques.
Proceedings of the second European shark and ray workshop. Tag and release
schemes and shark and ray management plans. S.L. Fowler and R.C. Earll (eds.).
Includes papers and abstracts of presentations ranging from individual tag and release
research programmes to larger cooperative programmes in Europe. Available from Dr
Clare Eno, JNCC, Monkstone House, City Road, Peterborough, PE1 1JY, UK.
The Shark Tagger Summary. Newsletter of the Cooperative Shark Tagging
Distribution of this semi-annual newsletter is limited to active participants in the
National Marine Fisheries Service (NMFS) Cooperative Shark Tagging Program. It
reports on tagging and return results and also on ongoing research projects being
undertaken by the NMFS. The newsletter is published by the US Department of
Commerce, National Oceanic and Atmospheric Administration, National Marine *
Fisheries Service, Northeast Fisheries Science Center, Narragansett, RI 02882, USA.
Wildlife Telemetry: Remote monitoring and tracking of animals. Priede, I.G., and
Smith (eds.). 1992. Ellis Horwood Ltd, London.
Handbook of biotelemetry and radio tracking. Amalner, C.J., and MacDonald, D.
W. (eds.). 1980. Pergammon Press, Oxford.
Nelson, D.R. 1990. Telemetry studies of sharks: a review, with applications in
In: Pratt, H.L., Gruber, S.H., and Tanuchi, T. (eds). Elasmobranchs as a living
resource: advances in biology, ecology, systematics and the status of the fisheries.
Proc. 2nd US-Japan workshop NOAA Technical Report 90. NMFS. 239- 256.
Nelson, D.R., et al. 1991. An acoustic tracking of a megamouth shark,
In: Abstracts of the American Society of Ichthyologists and Herpetologists 71st Annual
Meeting, and American Elasmobranch Society 7th Annual Meeting, 1991.
NOAAINational Marine Fisheries Service 1993. Workshop on tagging and
tracking technology. Reference Document 93-08.
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