Navigation Links
New study reveals vulnerability of sharks as collateral damage in commercial fishing
Date:7/22/2014

MIAMI A new study that examined the survival rates of 12 different shark species when captured as unintentional bycatch in commercial longline fishing operations found large differences in survival rates across the 12 species, with bigeye thresher, dusky, and scalloped hammerhead being the most vulnerable. The study, led by researchers at the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science and UM Abess Center for Ecosystem Science and Policy, provides new information to consider for future conservation measures for sharks in the Northwest Atlantic.

The unintentional capture of a fish species when targeting another species, known as bycatch, is one of the largest threats facing many marine fish populations.

Researchers from UM and the National Marine Fisheries Service analyzed over 10 years of shark bycatch data from the western Atlantic Ocean and Gulf of Mexico tuna and swordfish longline fisheries to examine how survival rates of sharks were affected by fishing duration, hook depth, sea temperature, animal size and the target fish. Some species, such as the tiger shark, exhibited over 95% survival, whereas other species survival was significantly lower, in the 20-40% range, such as night shark and scalloped hammerheads.

"Our study found that the differences in how longline fishing is actually conducted, such as the depth, duration, and time-of-day that the longlines are fished can be a major driver of shark survival, depending on the species," said UM Rosenstiel School Ph.D student and lead author Austin Gallagher. "At-vessel mortality is a crucial piece of the puzzle in terms of assessing the vulnerability of these open-ocean populations, some of which are highly threatened."

The researchers also generated overall vulnerability rankings of species taking into account not only their survival, but also reproductive potential. They found that species most at risk were those with both very slow reproductive potential and unusual body features, such as hammerheads and thresher sharks. The paper's authors suggest that bycatch likely played an important role in the decline of scalloped hammerhead species in the Northwest Atlantic, which has been considered for increased international and national protections, such as the U.S. Endangered Species List.

The researchers suggest that high at-vessel mortality, slow maturity, and specialized body structures combine for the perfect mixture to become extinction-prone.

"Our results suggest that some shark species are being fished beyond their ability to replace themselves," said UM Research Assistant Professor Neil Hammerschlag. "Certain sharks, such as big eye threshers and scalloped hammerheads, are prone to rapidly dying on the line once caught and techniques that reduce their interactions with fishing gear in the first place may be the best strategy for conserving these species."

The study, titled "Vulnerability of oceanic sharks as pelagic longline bycatch" was published online in the open-access journal Global Ecology and Conservation.


'/>"/>

Contact: Diana Udel
dudel@rsmas.miami.edu
305-421-4704
University of Miami Rosenstiel School of Marine & Atmospheric Science
Source:Eurekalert  

Related biology news :

1. Study by UC Santa Barbara researchers suggests that bacteria communicate by touch
2. Law that regulates shark fishery is too liberal: UBC study
3. New study will help protect vulnerable birds from impacts of climate change
4. Study jointly led by UCSB researcher supports theory of extraterrestrial impact
5. BYU study: Using a gun in bear encounters doesnt make you safer
6. 15-year study: When it comes to creating wetlands, Mother Nature is in charge
7. Pycnogenol (French maritime pine bark extract) shown to improve menopause symptoms in new study
8. Crystal structure of archael chromatin clarified in new study
9. EU-funded study underlines importance of Congo Basin for global climate and biodiversity
10. University of Houston study shows BP oil spill hurt marshes, but recovery possible
11. Study demonstrates cells can acquire new functions through transcriptional regulatory network
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
New study reveals vulnerability of sharks as collateral damage in commercial fishing
(Date:3/3/2016)... 2016  FlexTech, a SEMI Strategic Association Partner, awarded ... & Development, Leadership in Education, and, in a category ... th year of the FLEXI Awards and the ... from past years . Judging was done on ... of criteria, by a panel of non-affiliated, independent, industry ...
(Date:3/2/2016)... DUBLIN , March 2, 2016 /PRNewswire/ ... has announced the addition of the  "Global ... to their offering.  ,     (Logo: http://photos.prnewswire.com/prnh/20130307/600769) , ... sector to grow at a CAGR of ... http://www.researchandmarkets.com/research/wzwqtz/global_biometrics ) has announced the addition ...
(Date:3/1/2016)... , March 1, 2016  (RSAC Booth #3041) – ... a whopping $118 billion is lost to false positives, ... and inaccurate fraud detection. At the RSA Conference 2016, ... way companies handle authentication by devaluing the data fraudsters ... analytics. --> --> ...
Breaking Biology News(10 mins):
(Date:4/29/2016)... TURIN, Italy , April 29, 2016 ... version 5.11, the latest update to its industry-leading treatment ... has shown that Monaco version ... Users can now attain calculation speeds up to four ... Monaco . With the industry,s gold standard ...
(Date:4/28/2016)... Hill, Conn. (PRWEB) , ... April 28, 2016 ... ... of financing and ongoing support for Connecticut's innovative, growing companies, today announced the ... digital health and financial technology (fintech) companies. , “VentureClash looks to ...
(Date:4/28/2016)... ... April 28, 2016 , ... ... an open house for regional manufacturers at its Maple Grove, Minnesota technical center, ... Hardinge Group, Chiron and Trumpf. Almost 20 leading suppliers of tooling, accessories, ...
(Date:4/27/2016)... (PRWEB) , ... April 27, 2016 , ... The Pittcon ... Pittcon 2019. Chuck has been a volunteer member of Committee since 1987. Since ... the board of directors and treasurer and was chairman for both the program and ...
Breaking Biology Technology: