By Meghan Hurley
Just like the night’s sky, California’s oceans hold galaxies. A colorful collection of purple, orange and red sea stars rest in the shallow water of tide pools. These ethereal creatures move using hundreds of tiny tube feet, which gives them the illusion of floating, or drifting.
While these pools can provide us with the same awe as staring up into the constellations, the Pacific is losing its stars.
In 2013, many sea stars – also known as starfish – along the Pacific Coast mysteriously began to waste away. Their usual plump shape deflated. They lost their arms. Within a matter of days, sea stars afflicted with this disease, which is called sea star wasting, died. They literally dissolved into the ocean, melting away without a trace.
In 2020, the International Union for the Conservation of Nature declared sea stars critically endangered.
What’s worse, warming ocean temperatures are exacerbating the problem. A marine heat wave from 2013-2015 made the problem much worse, and as climate change accelerates, more sea stars are at risk. Sea star wasting disease has a cascading and devastating effect on Northern California’s underwater life. Without sea stars to eat purple sea urchins, the urchins are left to proliferate and devour all of the kelp. This decimates these swaying underwater forests. Tragically, kelp has declined by 95% along our state’s north coast since 2013, which is the year scientists began to detect the disease.
Sea star populations haven’t fully recovered since the disease outbreak.
Thankfully, there might be a way to make sea star habitat more livable: marine protected areas (MPAs). These are areas of the ocean that are protected from human use, ranging from places that allow fishing but don’t allow offshore oil drilling, to fully protected areas that prohibit any kind of harvest.
California has a network of 124 of these MPAs, established in 2012 under the state’s Marine Life Protection Act (MLPA). That means there are tide pools – and offshore areas – up and down the California coast that are protected. The network is subject to its 10-year review in 2022. For the sake of marine life, habitat and the opportunity to regenerate what we’ve lost, it’s essential that the state keeps these areas protected and protects more of them.
MPAs offer a glimmer of hope in more ways than one. First, they provide functional redundancy. This means that in the absence of sea stars, other sea urchin predators fill the gap left in the food web. Because these other predators faced fewer threats and less fishing pressure in protected areas, they were more able to effectively absorb the ecological role of sea stars and keep kelp forests alive.
In contrast, outside of MPAs, competing predators are smaller and less abundant and are unable to effectively compensate for the loss of sea stars. In those situations, kelp forests, and the wildlife that call them home, end up more degraded.
Second, new data from long term monitoring of the state’s network of MPAs shows that sea stars themselves have a better chance of survival within protected areas. Along the Central Coast, MPAs have higher populations of sunflower sea stars compared to areas that are not protected. The marine heat wave that decimated sea star populations occurred during the study period, but sea stars in MPAs were better able to withstand the disaster.
The morning light makes stars in the night sky disappear. But we’re comforted by the knowledge that when night falls, they’ll be back. We shouldn’t let these underwater stars drift away and dissolve into the ocean as if they were never there and never will be again. We need to safeguard marine spaces by maintaining and strengthening MLPA protections and keep the magic and mystery of the watery, celestial world alive.
Meghan Hurley is a conservation associate with Environment California. Her work is focused on protecting special, and ecologically important, marine areas in the Pacific, as well as the whales, dolphins, sea turtles and sea stars that call the Pacific ocean home.
Source: www.mercurynews.com