A loggerhead sea turtle (Caretta caretta) is accidentally caught during longline tuna fishing operations in Uruguay.
Releasing banner lines behind boats in Alaska longline fisheries has conserved thousands of seabirds from being unintentionally captured each year. Credit: Ed Melvin/Washington Sea Grant
Accidentally trapping sharks, seabirds, marine mammals, sea turtles, and other animals in fishing gear is among the biggest barriers to making fisheries more sustainable around the globe. Marine secured areas– areas of the ocean reserved to conserve biodiversity– are utilized, in part, to lower the unintentional catch of such animals, to name a few conservation objectives.
Many countries are requiring protection of 30% of the worlds oceans by 2030 from some or all types of exploitation, including fishing. Structure off this proposition, a new analysis led by the University of Washington takes a look at how effective fishing closures are at lowering accidental catch. Researchers found that long-term marine protected areas are a fairly inefficient method to secure marine biodiversity that is unintentionally captured in fisheries. Dynamic ocean management– changing the pattern of closures as unintentional catch hotspots shift– is far more effective. The outcomes were released on January 17, 2022, in the Proceedings of the National Academy of Sciences.
A loggerhead sea turtle (Caretta caretta) seen in the ocean near Uruguay. Dynamic ocean management, which would close parts of the ocean in accidental-catch hotspots, would assist secure turtles like this from being inadvertently captured throughout fishing operations. Credit: Philip Miller
” We hope this study will include to the growing movement far from permanently closed locations to encourage more vibrant ocean management,” stated senior author Ray Hilborn, a professor at the UW School of Aquatic and Fishery Sciences. “Also, by revealing the relative ineffectiveness of static locations, we hope it will make conservation advocates conscious that irreversible closed areas are much less efficient in reducing accidental catch than modifications in fishing techniques.” These strategies might consist of devices that keep sea turtles away from shrimp fishing, or banner lines on boats to discourage seabirds from getting caught in fishing lines.
The global group of scientists looked at 15 fisheries around the world– consisting of Californian swordfish, South African tuna, and Alaskan pollock– and designed what would happen both to the targeted fish and to species captured inadvertently, called bycatch, if 30% of fishing grounds were completely closed, compared to vibrant management. In practice, vibrant management tracks real-time information of bycatch and closes smaller areas that can move year to year based upon where types are most affected.
A loggerhead sea turtle (Caretta caretta) is accidentally captured during longline tuna fishing operations in Uruguay. Dynamic ocean management, which would close parts of the ocean in accidental-catch hotspots, would help prevent bycatch like this turtle. Credit: Philip Miller
Among the reviews of permanent marine safeguarded areas is that a number of the species they are expected to secure– marine mammals, turtles, seabirds– move around and may leave the protected location entirely. The study found that, typically for all fisheries studied, limiting fishing in 30% of a fixed location did lower bycatch by about 16%. But in dynamic closed locations, over the exact same portion of the ocean, bycatch was reduced by up to 57%.
” We found we can considerably reduce bycatch without reducing the catch of target types by closing little fishing locations that can move year to year,” stated lead author Maite Pons, an independent fisheries consultant based in Uruguay who finished this work as a UW postdoctoral researcher. “This vibrant approach is increasingly valuable as climate change drives types and fisheries into brand-new habitats, altering these interactions.”
The authors acknowledge that goals vary for numerous marine secured locations, and if the primary purpose is to safeguard a critical habitat, a biodiversity hotspot, or special feature, fixed closures may be more reliable and easier to enforce. In this way, all conservation objectives should be broadly considered when identifying which types of ocean securities to put in location, they said.
” I hope this research study motivates everybody to think about how finest to decrease bycatch and secure marine communities,” Hilborn added.
Referral: “Trade-offs in between bycatch and target captures in vibrant versus fixed fishery closures” 17 January 2022, Proceedings of the National Academy of Sciences.DOI: 10.1073/ pnas.2114508119.
A complete list of co-author names and institutions is listed in the paper. No outside funding was utilized in this research.
Scientists discovered that irreversible marine protected locations are a reasonably ineffective method to secure marine biodiversity that is accidentally captured in fisheries. Dynamic ocean management– changing the pattern of closures as unexpected catch hotspots shift– is much more reliable. Dynamic ocean management, which would close parts of the ocean in accidental-catch hotspots, would help safeguard turtles like this from being accidentally captured during fishing operations. These techniques might include gadgets that keep sea turtles away from shrimp fishing, or banner lines on boats to prevent seabirds from getting captured in fishing lines.