Bycatch (noun): Un-desirable marine life that’s caught by fishermen, and is tossed back into the sea dead or dying. Fishermen discard these fish because they are too small for regulations, or there is no market for the animal.
We live in a wasteful world there’s no doubt about it, but the loss of fish and other animals in our ocean due to poor fishing practices takes the cake.
Bycatch is a seriously wasteful phenomenon happening in ocean; but there are innovative solutions out there which can turn the tide for the conservation of these incredible species.
A Problem Of Epic Scale
- 40% of the world’s fisheries catch is discarded as bycatch.
- 4,600 sea turtles/year are caught as bycatch in the US alone.
- 50 million sharks/year are unintentionally caught.
- 160,000 seabirds/year die from longline bycatch.
- 2 billion pounds of food is wasted.
In short, commercial fishing indiscriminately catches all kinds of marine life from small fish to massive whales and sharks.
Modern fishing gears are very effective at tracking and catching life at sea. But with great power comes great responsibility! Now more than ever we need fisheries to change these trends.
Different Types Of Bycatch
- Trawl fishing: This is a type of fishing where nets are towed at the bottom of the ocean, scooping up everything that’s too big to escape! Since the nets are deep underwater, seabirds and marine mammals don’t often become caught, but juvenile fish, sharks, and other deep sea animals become victims.
- Gill-nets: In this type of fishing a net is placed out at sea in order to entangle a specific species of fish. Yet, while left at sea to ‘soak’, these nets kill hundreds of sea turtles, marine mammals and sharks as they become entangled underwater and struggle to breath.
- Long-Lines: This type of fishing deploys a long line of hooks and bait far out at sea to catch larger predatory fish. Unfortunately seabirds, sharks, sea turtles, and open water fish are snagged by these hooks and killed.
All the damage done by these industrial gears is fixable if people follow the rules and regulations set in place to protect ocean life. Scientists and fishermen have worked together to discover new methods of reducing bycatch without sacrificing profits.
One example of a solution to bycatch in trawl fishing is called a Turtle Excluder Device (a.k.a. TED). This (and other Excluder Devices) allow non-target species escape from the nets. They capture the money-making fish species while allowing larger animal like sea turtles to break-free and escape.
And these are proven to be very successful: reducing sea turtle bycatch by 90%!
Another solution is the Separator Device – which divides fish species when they encounter the net, offering non-target fish an escape.
One example is a grate being placed in shrimp gears to allow shrimp to pass to back of net, while releasing larger fish. Separating the catch within the net!
Another example is a net designed to separate cod and haddock. Cod swim down when they encounter the net, while haddock swim up. So to protect Cod from becoming Bycatch, the bottom of the net leads to an opening while the top of the net is captured.
Streamers are used to deter birds from biting the baited hooks of long-lines.
These may look ridiculously to the human eye but to the birds it looks like a barrier, keeping them at bay.
This has been able to save hundreds to thousands of seabirds lives, and is a very easy and cheap solution for fishermen to adopt. .
Even simple changes to the way hooks are shaped can make a life or death difference.
Circle hook designs prevent sea turtles and birds or other marine mammals from becoming stuck on a longline hook.
The slight change of the hook design has the ability save the lives of multiple marine life species. The hooks still have success catching target fish so it’s a “win win” for both the fisherman and the marine life.
One last solution to gillnet bycatch is to attach pingers to nets while they ‘soak’ in the water – to deter porpoises and dolphins, because the noise bothers them.
This solution only works for some species. Since marine mammals are such intelligent animals – they can view the pingers as a ‘dinner bell’, actually placing more of the population at risk.
Special thanks to TerraMar’s Education Development Intern – Vincent Migliore for his work in creating this guide to marine bycatch.