Quick Take
An influx of anchovies has been attracting pelicans and sea lions in recent days, but Senior Deputy Harbormaster John Haynes says that so far this year, it doesn’t appear that there will be a mass die-off of anchovies in the harbor – as there was in 2014. In an interview with Lookout, he described this year’s annual phenomenon and how the Santa Cruz Harbor addresses the influx of fish.
Monterey Bay is home to an abundance of anchovies, which feed on microscopic plankton and are fed on by other fish, seal lions and brown pelicans.
They’re an essential part of the local ecosystem, and yet, in extraordinary cases – most recently in 2014 – they can cause disastrous impacts if a mass die-off occurs in the Santa Cruz Harbor.
Most years, roughly between the months of July and October, schools of anchovies numbering in the many hundreds of thousands swim closer to the shoreline along the bay, and often thousands of them roam into and out of the harbor.
During those months, Senior Deputy Harbormaster John Haynes and harbor staff closely monitor the fish and oxygen levels to avoid a potential die-off. So far, things look good this year.
“We got a lot of fish in here,” Haynes said Monday. “Things are sustaining, the schools are just fine.”
He said there are a few factors that lead them to do that, but it’s not entirely clear why. When there’s a high amount of anchovies in the harbor and the oxygen levels fall too much, the fish get disoriented and weak, they’re unable to find their way out, and there can be a massive die-off. In 2014, harbor staff had to remove about 120 tons of dead anchovies and haul them to the dump.
“An anchovy die-off is such an expensive thing and has a lot of impacts to boaters,” Haynes said. “The water becomes really acidic during the decomposition, and so usually it will affect people’s bottom painting, which is usually copper-based. … And of course, the smell is just terrible, and that affects the businesses, especially the restaurants.”
Haynes said schools of anchovies regularly swim into and out of the harbor throughout the year, but it’s during the July-to-October period that larger numbers come in from the bay. He said when oxygen levels in the bay are low, they’ll move closer to the shoreline and the harbor for higher oxygen levels.
For a rough comparison to that 2014 season when harbor staff hauled out 120 tons of dead anchovies, he estimated that there are around 30 tons in the harbor right now.
To keep oxygen levels up, the harbor runs aerators – machines that pump oxygen into the water – and uses an oxygen monitor every couple of days. The oxygen levels are hovering just above concerning levels, and numbers are relatively low in the harbor, so the fish are staying healthy, according to Haynes.
With the harbor teeming with higher amounts of anchovies, Haynes said that sea lions – which regularly sleep on the docks and roam the harbor – have more interactions with boaters.
“We do have sea lions that are in the harbor being kind of obnoxious,” he said. “In some cases, they’re standing up and having a standoff between the boaters and them on the docks.”
Haynes said no boaters and no sea lions have been injured during those recent interactions.
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