What, you might ask, do pink czarinas and chameleons have to do with fishing. In fact, right about now you are probably asking what in the heck are pink czarinas? And no, they aren’t related to pink rabbits or even hidden leftovers from the Second Russian Revolution. No, they’re simply exotic little jellyfish.
In the summer of 1993 headlines in the Santa Rosa and Petaluma newspapers highlighted an invasion of small, pinkish-colored jellyfish into the turning basin of the Petaluma River. Apparently thousands of the tiny creatures had decided to visit the Wine Country. Scientists, and the merely curious, flocked to Petaluma looking for the small invaders and soon the word was out — they were a form of Russian jellyfish previously never encountered in California waters. Apparently (although it’s only speculation) they had hitched a ride on a ship visiting the Bay Area from the Black Sea and probably were deposited into San Francisco Bay from the ship’s ballast tanks. Soon after, the Chamber of Commerce got involved, promoted these facts, a name-the-creature contest ensued, and the little visitors became the “Petaluma Pink Czarinas.” The chamber, papers, and a lot of small children were pleased. No harm, no foul, right?
However, the invasion highlighted a serious and increasingly difficult part of managing the ecosystem of San Francisco Bay. Several alien species now call the Bay Area their home and unfortunately some are doing a lot of damage.
It shouldn’t come as a surprise! Many new and unusual species have been caught in the last couple of years due to the El Nino conditions. But the aliens I am talking about are species that, for the most past, have been accidentally introduced by man, most commonly in the ballast of ships.
In the last two years I have caught two species that fit this mold. The first is the smallish chameleon goby (Tridentiger trigonocephalus). These are small fish that most anglers would never catch or see unless they were using small hooks. But I have caught three of these Asian natives while fishing for perch in the Oakland Estuary. Another small fish is the yellowfin goby (Acanthogobius flavimanus). Last fall I caught two while fishing one morning near China Cove in San Francisco. Later, the same day, I caught two more of the gobies while fishing at the FDR Pier in Oakland. After fishing Bay Area piers for over twenty years, and never having caught a single yellowfin goby, I had caught four in a single day, and on opposite sides of the bay. Since then I have caught three more. What is going on? Consulting the standard references yielded the information that both fish are native of Asia, both are believed to have been brought to our waters in the ballast of ships (or with live seed oysters), and both are becoming more and more common in San Francisco Bay and Los Angeles Harbor. Luckily, neither of these seems to have done much damage although they do undoubtedly compete with native fish for food that is available.
More of a concern is the tiny little Asian clams. These clams began to show up in Bay Area and delta waters nearly twenty years ago and initially didn’t cause too much concern. However, following the drought years their numbers had expanded to the point where they were the main species in much of Suisun Bay and parts of San Pablo Bay. Occurring in masses as large as 2,000 per square meter, they dominated much of the bottom. Who cares? Well, they happen to eat much of the same microscopic food as small and immature fish, fish such as delta smelt and striped bass. Many are now wondering if a major reason why stripers are showing such a modest recovery is the fact that these clams are siphoning off much of the food that should be available to the baby stripers. And, there does not seem to be any solution to getting rid of these clams, at least at this time.
In similar water is the oriental shrimp, also called the Korean or pile shrimp (Palaemon macrodactylus), a species apparently accidentally introduced from the ballast of ships returning from Asia during the Korean War. This species is now fairly common in certain areas (such as Marin County) and competes with the two native species of shrimp that make up the supply of “grass shrimp” which are used by fishermen as bait. Since the original and once plentiful bay shrimp (Cragon franciscorum), and the smaller blacktail bay shrimp (Cragon nigricauda), are seen in fewer and fewer numbers, it is appropriate to ask what affect this new species has had on their populations. Has it harmed their population or is it simply an additional resource, which may be available as the others decrease?
Although a number of other species have found their way into our waters, these are probably the most numerous and the ones that warrant the most immediate attention. With the exception of the Asian clam (which is known to have an adverse affect on Suisun Bay), most of these have had only moderate study. Thus no one really has a good idea if the affect is negative, neutral or positive (unlikely).
Unfortunately the problem of accidentally introduced species is an ongoing problem and one that seems to have little solution in the immediate future. As long as there are large ships they will probably need ballast tanks, and as long as there are ballast tanks they will take in and disgorge unwanted species. Perhaps these waters could be dumped into the ocean versus inside the various bays, but even then there is no guarantee that all alien species would be kept out of local waters.
Finally, there is the issue of “intentional introductions.” The intentional introduction of alien species has, in some cases, been a resounding success. Certainly the actions of Livingston Stone (who introduced 150 striped bass into the Carquinez Strait near Martinez in 1879) would be judged successful by most Bay Area anglers. Likewise the introduction of several species of oysters and clams into western waters, especially the Japanese “littleneck clam.” However, other efforts have failed such as the attempt to introduce Atlantic lobsters into waters off the Golden Gate. Such lessons simply show the care that needs to be taken when discussion of such introductions take place. What will be the effect of the introduction? Unless there is a resounding positive outlook, it is probably far better to forget the idea.