Fishing ban won't protect kelp forests
I recently read an impassioned Sentinel Guest Commentary (April 4) urging support for the creation of new marine protected areas (MPAs) that would ban all fishing in the waters off of Natural Bridges past Four Mile Beach out to three miles offshore and in the kelp beds between Pleasure Point and Capitola. While I strongly agree with the writer's general sentiment that we need to protect the ocean from various threats, I feel compelled to highlight some specific inaccuracies in their scientific justification for these proposed MPAs.
As a marine scientist and ocean lover, I am not used to pushing back against efforts to protect the ocean. But, nothing is more frustrating than seeing good scientific research being misrepresented to bolster a preconceived agenda. So I got involved with a community group called Allwaters (allwaters.org) that is standing up for the responsible use of science and common-sense ocean conservation that maintains access for sustainable fishing. My experience in fisheries science has taught me that ocean conservation and responsible fishing practices can support each other.
Despite the previous writer's claim, there is little scientific evidence to support the idea that MPAs will protect Central California kelp forests from marine heat waves. A study published last month in the Journal of Phycology looked at MPAs around the world and found that kelp suffered during warm water events whether it was in an MPA or not.
Furthermore, these MPA proposals largely rely upon studies conducted in Southern California kelp forests, but the ecological dynamics in Central California kelp forests are fundamentally different. In Central California, it's sea otters (not fish) that exert top-down predatory control on kelp-hungry sea urchin populations – so we shouldn't expect fishing bans to benefit the kelp in our area. It's also important to note that the groundfish species anglers are targeting are harvested at sustainable levels, as assessed by the Pacific Fisheries Management Council.
Banning fishing off Pleasure Point and Natural Bridges will disenfranchise low-income anglers and youth who do not have access to expensive boats to target offshore fishing areas. It will likely concentrate fishing efforts onto the remaining easy-access kelp forests in Santa Cruz, potentially degrading what were historically healthy fishing grounds. Lastly, it will hurt the bottom line of local businesses such as Santa Cruz and Capitola boat rentals, as well as our sustainable, smallvessel, rod-and-reel commercial fisheries and fishmongers.
I'd like to see us spend more energy on alternative techniques to help our local kelp forests persist. Kelp is especially sensitive to poor water quality stemming from urban/ agricultural runoff, so actions like creating permeable urban surfaces that filter dirty water before it reaches the ocean would directly help the kelp (and surfers) off Santa Cruz. We could be helping scale the efforts of the Sunflower Star Laboratory in Monterey to bolster the population of one of the natural defenses we have against sea urchin overpopulation, unfortunately lost due to Sea Star Wasting Syndrome.
The reality is that this backand-forth banter is a little bit irrelevant. There is a comprehensive evaluation process by which the Fish and Game Commission will review the evidence for/against these new MPAs. It will consider the best available science, socio-economic effects, impacts to justice/diversity/inclusion/equity, and factors like law enforcement. It's not a popularity contest as much as it's a science fair, and as such I have confidence that these proposed MPAs will not meet the commission's threshold for approval.
Ethan Estess is a marine scientist and artist and worked for the Monterey Bay Aquarium for many years studying tuna ecology and conservation. He is best known for his monumental wave sculptures that raise awareness of ocean plastic pollution, working from his studio on Santa Cruz's Westside.