Posted on June 9, 2016
Posted on June 9, 2016
Consumers often ask us to describe various types of fishing gear and explain which ones cause the most destruction to the ocean. Another frequent question is why our seafood ratings for a particular species differ depending on the fishing method used. To help answer these questions, we decided to create a Fishing Gear 101 blog series. In this series, we describe how common types of gear work, what they catch, how they affect ocean wildlife and habitats, what technologies or regulations can help lessen the gear’s negative effects, and what we see as the path forward to ensure healthy oceans in the future.
We want to help seafood consumers, businesses, and chefs who use our seafood ratings better understand what the terms ‘trawl’, ‘longline’, or ‘handline’ really mean. We also hope Fishing Gear 101 will help everyone understand the collateral damage that fishing can cause to the ocean and the importance of choosing seafood caught in a responsible way.
Next in this series we are covering hand-held tools – including rakes, shovels, clam tubes, and tongs –that fishermen use to dig for clams, oysters, or other shellfish. These fishing methods allow fishermen to be selective about their catch. They can cause some disturbance or damage to bottom habitats, but overall are a much better alternative to dredges.
FISHING GEAR 101
Rakes, Shovels, Clam Tubes, and Tongs – Selective Diggers and Scoopers
What are rakes, shovels, clam tubes, and tongs?
Rakes and shovels are hand-held tools that fishermen use to dig for shellfish along the shore or in shallow waters. The simplest design consists of a long handle with a rake head or shovel blade attached to the end of it. In some cases rake tools may contain a basket that is used to hold the catch. Fishermen drive these tools into the bottom sediment to expose the target species and scoop them up.
Some fishermen will dig for clams with clam tubes (also called clam guns), which are 4-6 in. diameter tubes with a handle. Fishermen push the tube down into the sand, and then retract it to bring the clam onto the beach (see image below). Depressions in the sand made by the clam help fishermen identify where the clams are1.
A tong is essentially two rakes that have been hinged together. Fishermen commonly use tongs to collect oysters. When using hand tongs, fishermen lower the tong into the water from the side of a boat and feel around for a patch of oysters. When they come across a patch of oysters they will open and close the tong several times to detach the oysters from the oyster reef and scoop them up. Sometimes mechanical tongs are used (called patent tongs). The method is the same, but mechanical means are used to lower and raise the tong, and the rake heads are much larger2.
What do rakes, shovels, clam tubes and tongs catch?
Fishermen use these tools to catch bivalve shellfish (those with two shells), including clams, oysters, and mussels, that live in coastal habitats.
How do rakes, shovels, clam tubes, and tongs affect the ocean?
These fishing gears allow fishermen to selectively pick out their catch. Fishermen can typically return any non-target animals or undersized shellfish that are brought up in the rakes/shovels/tubes back to their habitat alive.
These gears can cause low damage to the fished habitats. Digging with rakes, shovels, and tubes can disturb animals that burrow in the sediment, such as worms, and may puncture the shells of non-target shellfish. Some studies have indicated that these fishing methods can cause an immediate decrease in overall animal abundance in the fished area3. Tonging for oysters may decrease the height and alter the structure of oyster reefs4. Oyster reefs provide important structural habitat for other ocean animals and help prevent erosion of the shoreline. But overall rakes, shovels, clam tubes and tongs are much less damaging to bottom habitats compared to dredges.
What can be done to lessen the negative effects of this fishing gear?
To reduce the negative effects of these hand-held shellfish tools on bottom ocean habitats, managers can set aside some areas for protection from fishing and can limit the overall amount of fishing through seasonal restrictions or catch limits.
The Path Forward
Rakes, shovels, clam tubes, and tongs are ocean-friendly fishing methods for catching shellfish, and are a great alternative to dredges. Whenever possible, fishermen should consider using these methods.
Shellfish caught with these methods are typically rated Green! Check out The Safina Center’s online seafood guide to view our seafood ratings.
Hooked? Check out the entire Fishing Gear 101 series here!
3.) The role of commercial digging of mudflats as an agent for change of infaunal intertidal populations, Journal of Experimental Marine Biology and Ecology; Disturbance of intertidal soft‐sediment benthic communities by cockle hand raking, Journal of Sea Research
4.) Biological effects of shellfish harvesting on oyster reefs: resolving a fishery conflict by ecological experimentation, Fisheries Bulletin; Conserving oyster reef habitat by switching from dredging and tonging to diver-harvesting, Fisheries Bulletin
Elizabeth Brown-Hornstein is a Research Scientist at The Safina Center.