SFB USA Joins Coalition To Study The Effects Of Seal Bombing On Whale Behavior In The Monterey Bay
Seal bombs are small explosive devices that fishermen use to scare predators away from their catch. (Credit: Photo courtesy of Anna Meyer-Loebbecke)
While continuing our work in the Marine Protected Areas in Malaysian Borneo, Stop Fish Bombing USA is lending our expertise and technology to an issue much closer to home: bombs in Monterey Bay National Marine Sanctuary. Seal bombs, originally intended for “pinniped deterrence” in fishing nets, are now routinely being used as a means to catch fish (squid and anchovies) by driving them into the purse seines. They are being used in places where cetaceans (whale, dolphin, porpoise) feed along the edge of Monterey Canyon with alarming frequency. Seal bomb use within Monterey Bay exhibits seasonal and daily patterns and can be pervasive at certain times, with up to 88 explosions per hour, 335 per day, and 1,188 explosions per month (Simonis et al., 2020). In Southern California, hydrophone data detected 37,500 blasts in one month, with an average of 12,000 blasts per month. The regulations governing this practice are outdated and poorly enforced.
Using seal bombs to deter marine mammals is legal, though using them to round up target species is not. (Credit: Photo by Kip Evans/Alamy Stock Photo, Hakai Magazine)
SFB USA is collaborating with Oceana, The Middlebury Institute Center for Blue Economy, and the Monterey Bay National Marine Sanctuary Research Program to document and address the impact of seal bombs. Our contribution would be to provide precise, real-time locations of the underwater seal bombs. Our underwater blast location technology uses time of arrival between internet-connected sensors with hydrophones. This has been proven in Malaysia where we help to reduce fish bombing. Researchers could then collate this information with whale tag movement in the area to determine the impact of the blasts on whale feeding behavior.
Our goal is to compile evidence and data to present to fishery managers including the California Fish and Game Commission, the Pacific Fishery Management Council, and the NOAA Protected Resources Division.
Click here to read the paper that brought the seal bombing issue in Monterey to our attention.