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:2/3/2017)... -- A new independent identity strategy consultancy firm announces ... Designed to fill a critical niche in technical and ... Mark Crego and Janice Kephart ... expertise that span federal governments, the 9/11 Commission, private ... expertise has a common theme born from a shared ...
(Date:2/1/2017)... Massachusetts , February 1, 2017 IDTechEx ... events on emerging technology, announces the availability of a new report, ... Continue Reading ... ... in industrial and collaborative robots. Source: IDTechEx Report "Sensors for Robotics: ...
(Date:1/26/2017)... , Jan. 26, 2017  Acuity Market ... for Biometrics and Digital Identity".  Acuity characterizes 2017 ... identity when increased adoption reflects a new understanding ... "Biometrics and digital identity are often ... Maxine Most , Principal of Acuity Market ...
Breaking Biology News(10 mins):
(Date:2/17/2017)... 2017  BioGenex, a global leader in molecular ... novel system for quantitative immunohistochemistry (IHC). The system ... Rochester (NY, USA) and Konica-Minolta Inc. ( ... able to accurately quantify the expression of an ... factor receptor-2) in clinical samples. Quantitative IHC is ...
(Date:2/17/2017)... , Feb. 17, 2017  Protagonist Therapeutics, ... data on its oral peptide drug candidates, PTG-100 ... of the European Crohn,s and Colitis Organization (ECCO).  ... Barcelona, Spain from February 15 ... detail preclinical data on Protagonist drug candidates PTG-100 ...
(Date:2/16/2017)...  ImMAGE Biotherapeutics (OTCMKTS: IMMG), an early-stage biotechnology company harnessing ... treatment for triple negative breast cancer (TNBC), announced today their ... program. The YEi Start in ... entrepreneurs grow their business in France ... selected to complete an intensive one week immersion in ...
(Date:2/16/2017)... , Feb. 16, 2017  ArmaGen, Inc., a ... therapies to treat severe neurological disorders, today reported ... with AGT-181, the company,s investigational therapy for the ... as mucopolysaccharidosis type I, or MPS I). The ... (POC) study, presented today at the 13 th ...
Breaking Biology Technology: