What We Can Learn from The Giant Sea Bass

Giant seabass swimming with kelp bass at the Torrey Pines Artificial Reef. Spring 2014.
Giant sea bass swimming with kelp bass at the Torrey Pines Artificial Reef. Spring 2014.

California’s largest bony fish is still considered critically endangered, but is making a comeback. Apparently California’s bans on deliberately targeting giant sea bass (since 1982) and near shore gill nets (since 1994) are having the desired effect (Pondella and Allen 2008). I suppose it isn’t so impressive that populations began recovering once people stopped killing these fish either on purpose or by accident, but it’s amazing that the killing stopped. Even better, the recovery of the giant sea bass can be used as a guide for how to save other similar large fish around the world.

Giant sea bass can weigh up to 553 pounds, move surprisingly quickly when properly motivated, and appear damn near invincible under water. Unfortunately, their behaviors and life-history traits nearly proved their undoing. While few sea creatures will mess with a fully-grown giant sea bass and adults can live for up to 76 years (Hawk and Allen 2014), female giant sea bass are not sexually mature until at least age 7. This makes this species vulnerable to overfishing both by increasing the amount of time it takes for individuals killed by fisheries to be replaced and increasing the odds that females will be killed before they ever reproduce in the first place. Giant sea bass also spawn in large groups in the same areas every year making the easiest time for humans to catch them exactly when they really should be left alone. Finally, giant sea bass also seemed to believe they were invincible and didn’t know that divers with spear guns were dangerous. To be fair to the fish, spear hunters tended to target spawning aggregations (Crooke 1992) and the sea bass were likely somewhat distracted.

Unfortunately many large fish including groupers, humphead wrasses, and totoaba are threatened by overfishing and share the giant sea bass’ characteristics of late sexual maturity, forming predictable spawning aggregations, and the inability to recognize divers as dangerous. While some of these species may require a California-style total fishing ban in order to be saved others may only require the restriction of other high-bycatch fisheries and rules against fishing on spawning aggregations. They would also benefit from a change in human attitudes in their habitat similar to the one that has taken place in California. While Californians in the 1970s shot giant sea bass with spears as proof of ‘rugged hunting prowess’ (at least as much can be shown by shooting a non-aggressive fish that doesn’t know to swim away), Californians in the 21st century shoot these magnificent fish with cameras as proof of artistic ability and ecological enlightenment.

Sources:

Crooke, SJ. 1992. History of giant sea bass fishery. p. 153-157. In California’s Marine Resources and Their Utilization. W. S. Leet, C. M. Dewees, and C. W. Haugen, eds. University of California Sea Grant extension publication (UCSGEP-92-12) Davis, California.

Hawk, HA and Allen, LG. 2014. Age and growth of the giant sea bass, Stereolepis gigas. CalCoFI, 55. giant seabass lifespan

 Pondella II, DJ and Allen LG. 2008. The decline and recovery of four predatory fishes from the Southern Califorina Bight. Mar Biol 154, 307-313. no gill nets seabass recover

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