Skates and Rays in Atlantic Canada

by Hilary Goodwin

Skates and rays are often referred to as “flat sharks”. They are the lesser known chondrichthyans, a class of fish that includes sharks, sawfish, and chimaeras. Skates and rays are part of the batoid superorder, which is composed of 574 species. That’s more species than all nine orders of sharks combined! Batoids are cartilaginous fish like sharks, but tend to inhabit soft benthic environments. In Canada, batoids range from the Northern Labrador Sea down to the Bay of Fundy and Georges Bank and can be found in a wide range of depths up to 4,000 m.

You may be surprised to learn there are 14 skate and 4 ray species in Atlantic Canada – for more details on the diversity of skates and rays, please visit the WWF Identification Guide to Sharks, Skates, Rays and Chimaeras of Atlantic Canada – http://awsassets.wwf.ca/downloads/identification_guide_to_sharks__skates__rays_and_chimaeras_of_atlantic_canada.pdf.

There are two main differences between skates and rays – where they live and how they reproduce. Skates are present at higher latitudes and in deeper waters while rays prefer shallower and warmer temperate to tropical waters. To reproduce, skates produce egg cases (oviparous) while rays produce live young (viviparous).

The Bedford Institute of Oceanography and the Department of Fisheries and Oceans (DFO) have undertaken studies on skate ageing, reproduction characteristics, and population trajectories. Without these types of studies, it is difficult to adequately manage skate populations in Atlantic Canadian waters. As skates are both targeted and caught as bycatch, they have been the more studied batoid.
Some scientists have argued that skates (Family Rajidae) are the most vulnerable of exploited marine fishes. Between 2005 and 2012, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) has assessed four species of skate, including their sub-populations – Winter skate (four sub-populations), Barndoor skate, Smooth skate (four sub-populations), and Thorny skate.

Summary of COSEWIC assessments for Atlantic skate species

Scientists estimate that Winter, Thorny, and Smooth skate populations have declined as much as 90 percent off the Eastern Scotian Shelf since 1970. Even though a sub-population species of Winter and Smooth skate have been assessed as endangered and threatened, no skate species have been listed under the Species at Risk Act (SARA). The consideration to list Winter skate under SARA in 2008 failed, and recovery targets for Winter skate have not been set.

Winter skate

Atlantic Torpedo Ray © Sue Scott

 

 

 

 

 

 

 

 

For more information on skate fisheries, discards, and management, please tune into next month’s blog on skate management in Atlantic Canada.

 

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This year at NAFO…

This gallery contains 2 photos.

by Hilary Goodwin Last week, the Northwest Atlantic Fisheries Organization (NAFO) met in Halifax, Nova Scotia for their annual meeting. NAFO, an intergovernmental fisheries science and management body, is the only Regional Fishery Management Organization (RFMO) to have an elasmobranch … Continue reading

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First Shark Encounter Series: Scott Seamone

I have been in the water with 11 different species of sharks in an array of marine settings. I am currently conducting research on the spiny dogfish shark, and I aspire to study at the graduate level. My ultimate goal is to help raise awareness about sharks to others.

Many people ask me, why study sharks? In response, I decided to connect with ShARCC and Pawn Media to make a video that would explain the most influential day of my life. All of the scuba diving footage came from one single day, in the dark, green, cold, temperate waters of the South Atlantic in Cape Town, South Africa.

If you have questions or comments about the video, or my experience with sharks, please fill out a comment box below, and I will respond as soon as I can.

Thank you for watching, and enjoy taking part in one of the most influential days of my life.

Produced and written by: Scott Seamone, ShARCC Intern

 

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CITES: International Protection for Sharks and Rays

CITES has been all over the news lately…but what is it and why is it important?

For many of you, like me, you’re aware that CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora) took place in Bangkok, Thailand from March 3 – 14, 2013. To clarify things, below is a short summary about CITES and why it’s important to the conservation of the sharks, skates and rays we all love!

CITES, a multilateral treaty drafted as a result of a resolution at the 1963 International Union for Conservation of Nature (IUCN), aims to ensure international trade of specimens of flora and fauna does not threaten the survival of the species in the wild.

In the last 40 years, CITES celebrated its 40th anniversary at the 16th meeting of the Conference of the Parties (CoP16), has grown to 178 Parties (members) and has managed to provide varying degrees of protection to 34, 000 species of plants and animals, including the Elasmobranchii; Cetorhinus maximus (Basking shark), Carcharodon carcharias (Great White), and Rhincodon typus (Whale shark), and as of 2013, Sphyrna lewini (Scalloped Hammerhead), Sphryna Mokkaran (Great Hammerhead),  Sphyrna lewiniunder (Smooth Hammerhead), and Lamna nasus (Porbeagle shark), all listed under Appendix II.

Now you may be thinking – “what’s an Appendix?!”

CITES provides three degrees of protection to species; the species are placed into categories (Appendices) based on the level of protection agreed upon by the Parties. (See the table below).

Table 1: CITES degree of protection for flora and fauna.

To see a summary table of Appendices I, II and III click here: http://www.cites.org/eng/app/appendices.php

FINALLY, here’s what happened at CITES CoP16:

The Parties participating in Committee I reviewed this working document on Sharks and Stingrays prior to meeting on March 11, 2013.

SIDE NOTE:

  • Committee I – discusses and makes recommendations concerning proposals to amend the appendices, quotas, and other scientific issues
  • Committee II – discusses and makes recommendations concerning the implementation and operation of CITES

On March 11, 2013 Committee I met and discussed 5 proposals. This Draft Amendment to Resolution 12.6 (rev. CoP16) and Draft Decisions of the Conference of the Parties was produced. (See description of Proposals below).

Table 2: Description of the five CITES proposals for sharks and rays, 2013.

On March 14th, 2013 CITES held a closing plenary session (a meeting of all Parties) where there was the potential for any of the above proposals to be re-opened for discussion if 1/3 of the Parties voted to do so. During the plenary, debate climaxed as an attempt to re-open the proposals on Sharks and Rays was narrowly defeated.

This means all five species of shark AND mantas were accepted for protection under Appendix II. Moving forward, countries that directly and indirectly fish these species must provide evidence that ensures Oceanic Whitetip, Porbeagle and Scalloped, Smooth, and Great Hammerhead sharks are harvested sustainably and legally. Trade of these species will be regulated through the use of CITES export permits. An export permit will only be issued if the specimen was legally obtained and export will not be detrimental to the survival of the species. It is now up to the individual Parties to enforce the provisions of CITES and to prohibit trade violations. Canada (and each individual Party) will now be responsible for penalizing trade and possession of the five newly protected species of sharks and two species of manta.

In the end….CITES CoP16 accepted 55 proposals, rejected 9 and 6 were withdrawn and strong enforcement measures to fight wildlife crime were adopted.

Next meeting will be held in South Africa in 2016.

Written by: Beth Watson, ShARCC Social Media Intern

Supplementary Information:

CITES : http://www.cites.org/; TRAFFIC: http://www.traffic.org/

For the complete Taxonomic Checklist of all CITES listed Shark and Fish species look here: http://www.cites.org/eng/cop/16/doc/E-CoP16-43-01-A2.pdf

Working Document on Sharks and Stingrays: http://www.cites.org/eng/cop/16/doc/E-CoP16-61.pdf

Draft Amendment to Resolution 12.6 (rev. CoP16) and Draft Decisions of the Conference of the Parties was produced: http://www.cites.org/common/cop/16/com/E-CoP16-Com-I-10.pdf ;

For the complete Summary Record of the 11th session of committee I on March 11th:http://www.cites.org/common/cop/16/sum/E-CoP16-Com-I-Rec-10.pdf (proposals 42 – 43) http://www.cites.org/common/cop/16/sum/E-CoP16-Com-I-Rec-11.pdf (proposals 43 – 46)

Acronyms

FAO – Food and Agriculture Organization of the United Nations

RFMO – Regional Fisheries Management Organization

IWMC -World Conservation Trust

CMS – Convention on Migratory Species

IUU – illegal, unreported, and unregulated

IPOA – International Plan of Action for the Conservation and Management of Sharks

NPOA – National Plan of Action for the Conservation and Management of Sharks

COFI – FAOs Committee on Fisheries

IUCN – International Union for the Conservation of Nature

WG – working group

 

*If you have comments or questions, please respond below, and I will reply as soon as possible.

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The Tagging of Pacific Predators

In the year 2000, a ‘decade of discovery’ of the marine world began. A total of 2,700 scientists, 80+ nations, 540 expeditions and $650 million (US) collectively made up what is known as the Census of Marine Life. This census was comprised of 17 main projects and 7 affiliated projects, that produced 2,600+ publications, described 6,000+ new species and 30 million species distribution records and counting. Information regarding sharks can be found in many of these projects; however, sharks were a major focus in the Tagging of Pacific Predators research program – TOPP.

Researchers from Canada, the U.S., Australia, Mexico, France, the UK, and Japan joined forces to create TOPP, which set out to study the migration of marine fishes, reptiles, birds, cetaceans and cephalopods throughout the North Pacific Ocean. TOPP provided valuable information on the ecological functions of the Pacific Ocean, including feeding and breeding hot spots, in addition to migration pathways.

Picture 1: Salmon sharks annually patrol Pacific waters from California to Alaska. Photo Credit: NOAA

Scientists involved in TOPP used ARGOS satellite tags and pop-up satellite archival tags (PSATs) (see photo below) to study the migration of most Pacific sharks. These devices are attached to the animals externally. Once these devices reach the surface the information is sent to the ARGOS satellite. Satellite tags are permanently attached to the dorsal fin of the shark (unless removed by researchers), and transmit information to the satellite when the dorsal fin breaches the surface. In contrast, PSATs are temporarily attached to the shark. After a given period of time, the tag pops off and floats to the surface where the signal is then sent to the satellite. PSATs and satellite tags were used to monitor the movements of salmon sharks (Lamna ditropis), blue sharks (Prionace glauca), thresher sharks (Alopias vulpinus), shortfin mako sharks (Isurus oxyrinchus), and great white sharks (Charcharodon carcharias).

Picture 2: PSATs getting ready for deployment. Photo Credit: WikiCommons

The Tagging of Pacific Predators project logged more than 50,000 tracking days of Pacific shark migration. They have identified a region off the southern coast of California known as the California Current System (CCS) as a seasonal, ecological hot spot used by all sharks. The CCS extends from San Diego north to San Luis Obispo and westward over 500 km. The great white shark migrates back and forth from the CCS to the oligotrophic regions of the central Pacific. The migration patterns of mako, blue and thresher sharks overlap, as all three use the CCS throughout the North American continental shelf. Finally, the salmon shark migrates the greatest distance, moving between the CCS and the cold northern waters of Alaska. Research to further understand Pacific shark migration continues to this today.