Whales, Seamounts, and Fisherfolk: How Conservation Efforts are Attempting to Tackle a Growing Threat to Marine Life

Hidden beneath the waters off the California coast lies a treasure trove of marine biodiversity. Seamounts, or underwater mountains, are veritable hotspots for a wide variety of undersea critters who call deep-sea ecosystems home. These steep peaks often break up ocean currents, allowing for nutrients to be brought up from deeper waters,[1] supporting an incredible array of unique life in the waters above.

Seafloor image of Pioneer Seamount off the central California coast. Image: Marine Conservation Institute, Data: MBARI

Part of what makes these seamounts so special is the presence of large marine mammals like whales, who flock to the large quantities of food present. Endangered populations of humpback whales are thought to rely on seamounts as an important rest and feeding stop along migration routes, and common dolphins seek out seamounts following their favorite foods.[2], [3]  Blue whales, gray whales and beaked whales are also among the marine mammals who take advantage of the incredible biodiversity surrounding these underwater mountains. Although the seamounts themselves are offshore, many whales will venture closer to shore while migrating or following prey. This puts whales at increased risk of interactions between humans.

In recent years, California and the entire west coast has seen a drastic increase in the number of whale entanglements in fishing gear. “On average, about 10 large whales were reported entangled along the West Coast each year between 2000 and 2012. In 2015, a total of 61 whales were reported entangled off the coasts of Washington, Oregon, and California.”[4] Although whale entanglements aren’t frequently reported, a majority of whales show scarring as evidence of past entanglements.[5] This suggests that more often than not, whales are interacting with fishing gear and escaping on their own.

Photo by Joe Platko

The National Oceanic and Atmospheric Administration (NOAA) and fisherfolk are working diligently to reduce the growing entanglement problem. The National Marine Fisheries Service (NMFS) of NOAA has an entanglement hotline for reporting sightings of tangled whales. This provides NMFS the opportunity to not only track the whale’s activity, but also to potentially send out a team of trained experts to help remove the derelict fishing gear. The fisherfolk themselves are also very concerned about this issue, and helped produce a best-practices document outlining several measures fishers can take to help reduce risk for the 2016-2017 season.

While NOAA is working to reduce the growing nearshore entanglement program, groups like Marine Conservation Institute are working to secure strong protection for the offshore seamounts and surrounding waters. The human threats to, and biological richness of, these deep-sea treasures is why Marine Conservation Institute and other members of the California Seamount Coalition are working to secure protection for California’s seamounts that would safeguard their ecological and cultural value from the threats of oil drilling, mining and other industries.

 

References:

[1] http://oceanservice.noaa.gov/facts/seamounts.html

[2] Garrigue et al., 2015

[3] Morato et al., 2008

[4] Matt Ellis, http://www.nmfs.noaa.gov/stories/2016/07/whale-entanglement.html

[5] Groom and Coughran, 2012

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