Finding of rare seahorse seen as a good sign for Upper Newport Bay

Local environmentalists point to last month’s discovery of a rare Pacific seahorse in the Upper Newport Bay Ecological Reserve as a sign that eelgrass restoration efforts are improving the area’s ecosystem.

A group of local students and adults went out on a boat in Upper Newport Bay on May 7 as part of the Back Bay Science Center’s monthly Marine Life Inventory program to catalog the types of fish and other creatures found in the water.

Marine researchers and educators use the data to look at seasonal and long-term trends in water quality and the abundance of fish and invertebrates. The goal is to monitor the effects of humans and environmental changes on the ecosystem.

Members of the group dragged a net along the muddy bottom of the bay. When they pulled it up, instead of the usual stingrays, worms and clams they normally find, a Pacific seahorse was inside.

The seahorse measured about 6 inches tall, according to Robin Madrid, education program coordinator for the California Department of Fish and Wildlife. The species can grow to about a foot tall.

“It’s very rare that we would find one in Upper Newport Bay,” she said.

The last time the species was found in the reserve was between 1999 and 2000. This is only the 10th reported sighting north of Baja California since the 1800s, according to Madrid.

The Pacific seahorse, or Hippocampus ingens, is typically found in the Pacific Ocean between San Diego and Peru, but it is sometimes driven farther north because of warmer El Niño waters.

Since 2012, the seahorse has been categorized as a vulnerable species, or one that is likely to become endangered, by the International Union for Conservation of Nature.

The species’ population has steadily decreased since the early 2000s, and dropped by 50% between 2007 and 2012, because of overfishing for Chinese medicine and for private use in fish tanks, experts say.

Declines in sea grass beds also can contribute to the decrease.

The Pacific seahorse, which is not a strong swimmer, relies exclusively on sea grass, including beds of eelgrass, and on coral reefs for its habitat, often curling its tail around blades of grass to avoid being swept away by changing tides.

Since 2012, Costa Mesa-based nonprofit Orange County Coastkeeper has been leading the charge in Upper Newport Bay to replant eelgrass, a form of underwater grass with green, slender blades that can help improve water quality and provide a suitable habitat for marine life.

Eelgrass was present in Upper Newport Bay before 2007, but poor water quality contributed to its demise, said Sara Briley, marine restoration director with Coastkeeper.

So far, the group has planted 1,300 square meters, or 0.3 acres, of eelgrass in Upper Newport Bay, Briley said.

“The most exciting part for us was that the seahorse, a species that really needs help, was found in our eelgrass beds,” Briley said. “It shows that our eelgrass restoration effort is providing homes not only for native species but other species from outside of the area as well.” ¿

hannah.fry@latimes.com

Twitter: @HannahFryTCN