Recreational shark fishery and tournaments
The Maritimes Recreational Shark Fishery has been active since 1994. Biological data collected from the recreational fishery is used to develop an assessment of stock status and the general health of the population, particularly that of blue sharks. For the purpose of scientific data collection, participants of the recreational shark fishery are required to provide information on length, weight, sex and location of every shark that is caught, whether or not it is landed or released. By monitoring trends in this data from year to year, and in conjunction with the more detailed information collected at local shark tournaments, the scientists at the Canadian Atlantic Shark Research Laboratory are able to detect population-level changes which are indicators of low stock abundance or overfishing. Biological indicators such as the size composition, size at sexual maturity and catch per fishing effort are particularly useful for detecting problems with the population. While there are social and economic benefits to a healthy shark fishery, the fishery must be sustainable over the long term. In other words, the populations of each of the shark species must be conserved at safe levels.
Shark fishing tournaments are held each year in waters off Nova Scotia, usually during the month of August. These are commercial or community-sponsored events, and are not sponsored by DFO or the Canadian Atlantic Shark Research Lab. However, the catches provide excellent samples for scientific examination, and thus all catches are closely monitored. The species most often caught is the blue shark. However in the past, the occasional thresher or porbeagle shark was also caught. Shortfin mako sharks, like the one in the photo (right), are not uncommon in Canadian waters, although this particular specimen is unusually large. Other species of shark do occur in Nova Scotian waters. However many of them prefer warmer waters that are associated with the Gulf Stream, or deeper waters which make them unlikely to be caught by recreational anglers.
Other Institutions projects and Research
OERS Shark Research Program
The Oceanographic Environmental Research Society (OERS) studies the impact of different pollutants in marine animals and their environment. Pollutants, such as heavy metals (mercury, lead, arsenic, cadmium, etc) are studied as they are toxic to animals. These heavy metals can be carcinogenic (arsenic, chromium), detrimental to the central nervous system (mercury), or cause other fatal results. To date, we have a long-term research program studying the amount of heavy metals in whales and seals, and in recent years we are focusing on sharks as they are important sentinel species in the marine environment. Different tissues samples are taken (skeletal muscle, liver, heart, kidney, gonads) from each animal to identify the heavy metal content. This information is important to our understanding of how pollutants are affecting the biology of many species and may give an indication to the 'health' status of the marine environment.
Dalhousie University, Faculty of Agriculture
Department of Animal Science and Aquaculture
Studies are planned to determine the effects of shifting ecosystems on sharks living in Canada’s northwest Atlantic Ocean. The stomach contents of blue sharks collected in the summer of 2018 and those of porbeagle sharks collected from the commercial fishery in 2017 will be identified. This research will replicate one study conducted in 1999-2001 in porbeagle sharks (Joyce et al., 2002. J. Marine Sci. 59: 1263-1269) and another conducted in 1999-2001 (McCord and Campana, 2003. J. Northw. Atl. Fish. Sci. 32: 57-63) and will be used to identify changes in the diets of these fish in the span of 17-19 years.
With the use of next generation sequencing, the microbiome of blue sharks in Atlantic Canada will also be determined, based on samples collected at sharks landed in 2017 and 2018. This work will serve as a baseline for future studies, as changes in the microbiome over time are indicative of many factors, including diet. In conjunction with this work, the presence of antibiotic-resistant bacteria in the digestive tracts of these sharks will also be determined. This will be a continuation of work conducted by our research group on samples collected in 2017, which determined that there are antibiotic-resistant bacteria present in the digestive tracts of blue sharks.
Recreational Shark Fishery
If you are planning to fish recreationally for sharks, you will need to apply to DFO for a licence. Those who already have a licence can download the Recreational Shark Fishery Summary Document, Instructions for Completing the Recreational Shark Summary Document, or an example of a completed summary document. Additional information (including how to identify the species of your shark or determine its sex) is also available here (Additional information).
Below is a map of the area just off Halifax along with the location of many of the blue sharks that have been caught during recent Halifax-Dartmouth shark tournaments. Blue sharks are usually caught using squid, mackerel or herring as bait and in water depths of at least 100 feet (preferably deeper), although the bait is fished relatively near the surface. Some fishers chum the water first to attract any sharks that are nearby. Water temperatures above 18 degrees Celsius are usually associated with greater catches.
The number of shark tournaments and participants has varied over the years since their inception, and biological data has been collected at each of them every year. Most of the sharks caught during the tournaments are released, with the majority of undersized sharks being tagged by volunteers. Of the sharks that are landed, lengths, weights, sexual maturity and stomach contents can be recorded and analyzed. Vertebrae are sometimes collected for age determination. The data collected up until 2004 has now been analyzed and a first report on the impact of shark tournaments on the health of the blue shark population has been published. The report Influence of Recreational and Commercial Fishing on the Blue Shark (Prionace Glauca) Population in Atlantic Canadian Waters (CSAS resdocs - 2004/069) found that blue sharks caught at shark tournaments accounted for only 3% of the blue sharks killed annually in Canadian waters, and thus were having a negligible effect on the population. Accidental bycatch from commercial fisheries was the major source of fishing mortality on blue sharks, and was probably responsible for a recent modest decline in population numbers. Almost all of this mortality comes from foreign boats fishing outside of Canadian waters. Nevertheless, the Shark Research Laboratory will continue to monitor the population closely.
Beginning in the summer of 2006, the rules for all tournaments were changed. Under the new rules, all blue sharks less than 240 cm (8 feet) are to be released alive, preferably after tagging. Tagging is voluntary, but is strongly encouraged by DFO Science, and a tagging kit is provided to all fishing captains before the start of the tournament. Along with tag number, tournament participants report information such as length, sex, location and water temperature on their tagging forms, which are turned in to DFO biologists at the end of each tournament fishing day. Sharks larger than 240 cm (8 feet) can continue to be landed, as can sharks of any size other than blue sharks. Live release of porbeagle sharks, which have been listed as endangered by COSEWIC, is also encouraged. The large numbers of sharks tagged by tournament participants will be of great scientific value to DFO Science, since the recapture rates will be used to provide better estimates of blue shark mortality rates. Click here for information on tag recaptures.
Number of catches per year
The number of sharks caught per year at each tournament can be found in the table below. Note that the rules for landing sharks at tournaments were changed in 2006, which resulted in fewer sharks being landed.
|Year||Tournament||Number of Sharks Caught||Number of Participants|
|2011||Petit De Grat||13||76|
|2012||Petit De Grat||20||112|
|2013||Petit De Grat||30||76|
|2014||Petit De Grat||35||113|
|2015||Petit De Grat||15||173|
|2016||Petit de Grat||9||135|
|2017||Petit de Grat||8|
|2018||Petit de Grat||4||120|
|2019||Petit de Grat||13|
Total weight landed per year
The total weight landed per year at the blue shark tournaments can be found in the table below. Note that the rules for landing sharks at tournaments were changed in 2006, which resulted in fewer sharks being landed.
|Year||Total Round Weight Landed (kg)|
Interesting shark tournament statistics
- Heaviest shark: A 492 kg (round weight) mako at Yarmouth 2004
- Heaviest blue shark: 211 kg (round weight) at Riverport 2008
- Longest shark: 366 cm (total length) at Split Crow 1996
- Average size of blue shark caught: 50 kg (round weight), 193 cm forklength
- Overall sex ratio: 50% male, 50% female
- Other species landed: 186 kg (round weight) thresher at Brooklyn 2008 and 132 kg (round weight) porbeagle at Yarmouth 2003
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