By Dr. Jan Freiwald, Reef Check California Director and Dan Abbott, Central California Regional Manager
On Thursday December 7th, the California Fish and Game Commission unanimously voted to close the Northern California recreational red abalone fishery for one year. Reef Check, in collaboration with the Partnership for Interdisciplinary Studies of Coast Oceans (PISCO), provided red abalone and ecosystem data that helped the Commissioners make an informed decision. Their decision was made in response to deteriorating ecosystem conditions along the North Coast experiencing a collapse of the kelp forest and abalone densities far below the minimum density required by the current fishery management rules to allow fishing. However, the Commissioner did not make this decision lightly given how economically important the abalone fishery is to communities along the North Coast and how valued abalone fishing is as a cherished tradition by divers and shore-pickers throughout California. Given the fishery's importance, the December Fish and Game Commission meeting was well attended and only after an engaged debate with the public did the Commissioners decide on a cautionary course of action in order to protect the resource with the hope that this will provide a sustainable fishery in the future.
The decision to close the last remaining abalone fishery in California was made against a historical backdrop of failing abalone fisheries. In the past, fisheries were not closed until populations were too low, so that even after decades of protections, populations have still not recovered to levels that could support a sustainable fishery. Abalone are slow growing and often go several years without spawning, which makes them susceptible to overharvest and slow to recover from overfishing. Abalone need to be in close proximity to successfully spawn and are relatively stationary so if populations get thinned out, the remaining individuals may not be able to produce offspring, even if they are healthy. These factors contributed to the overexploitation of other abalone stocks in the state which resulted in the closure of all abalone fisheries south of the Golden Gate in 1997. Sadly, even this drastic action seems to have been too late. Although populations have increased in the intervening 20 years, stocks are still considerably below levels that could support a sustainable fishery. The red abalone fishery in northern California was allowed to stay open because, unlike the southern abalone fisheries which allowed the use of scuba equipment and commercial take, the abalone fishery north of the Golden Gate was recreational only and was limited to shore pickers and breath-hold divers. This reduced the number of abalone that were taken to sustainable numbers and provided a deep water refuge below free diving depths. Today, it is clear that the management of this fishery did not cause the collapse of the abalone populations along the North Coast and that this closure is the result of unprecedented environmental change in Northern California's kelp forests.
The problems in the North Coast's kelp forests began in 2013 when Sea Star Wasting Disease decimated sunflower star (Pycnopodia helianthoides) and giant spined star (Pisaster giganteus) populations. At the same time as the onset of the wasting disease, the main large species of kelp on the North Coast, bull kelp (Nereocystis luetkeana), disappeared. It is likely that climate change and the unusually warm oceanographic conditions referred to as the "Warm Blob" played a role in reducing growth of kelp and/or leading to reproduction failures. Regardless of the initial reason, the deterioration of kelp forest ecosystems is the result of the combination of these events. In Northern California, sunflower stars are the main predators of sea urchins, and their decline has had wide-spread consequences for the kelp forest ecosystem. The loss of bull kelp and sea stars was followed by a sharp increase in purple urchin abundance. Urchins play an important role in kelp forest ecosystems but when their numbers explode, these voracious kelp consumers quickly turn areas of lush kelp forests into barren rock and prevent kelp forests from growing back. This has a cascading effect on other species that depend on kelp for food and habitat, including many species of fish and invertebrates such as abalone. Like urchins, abalone feed on kelp and the loss of kelp has left the abalone population starving and dying. All of these ecosystem changes, including the disappearance of sea stars, increase in urchins, loss of kelp and decline in abalone were documented in Reef Check's data which was presented to the Fish and Game Commission prior to their decision on the abalone fishery.
Reef Check witnessed the first warning sign in 2014 when we observed abalone leaving their protected refuges in cracks and crevices, moving out on to the open reef and into shallower water in search of food. This was followed by observations of under-nourished abalone and finally, dead abalone were observed on the ocean floor and washed up on beaches with some areas littered with dozens of empty shells. Since then, urchin densities have increased over 100-fold. Urchins are more resilient to the loss of their food than abalone and can survive for a long time without feeding. Therefore, it is unlikely that we will see a return of healthy kelp forests and healthy abalone populations until the sea urchins decline. Returning predators, disease or changes in environmental conditions could all cause sea urchin populations to collapse. In the meantime, the California Department of Fish and Wildlife has been conducting feasibility studies on removing urchins from small areas to maintain small patches of healthy kelp so that when a large scale change occurs, there is enough kelp to reseed the miles of coast that are currently barren.
The Commission decided to close the red abalone fishery in response to this environmental disaster in order to manage for long-term sustainability and to reduce additional pressure on the surviving populations. It is hoped that the remaining healthy abalone will help the recovery of the population so that the fishery can be reopened. The Commission will review their decision in 2018 when new data will be available and a new Fisheries Management Plan should be in place. Reef Check plans to continue to collect data on the health of the North Coast's kelp forest and to support sound, science-based management of the red abalone fishery.