This question was the bane of my existence for the three years I spent on my master’s degree and continues to plague me today while explaining my research to well… anyone. White croaker aren’t a large charismatic predator like a white shark or tuna. They aren’t considered a pretty (or for that matter intelligent) fish. Anglers don’t go out hoping to catch themselves a nice big fat croaker to take home and brag about and you probably won’t ever see one hung on someone’s wall. White croaker are just not… sexy. This fact was overbearing at scientific conferences where the room was always packed for those charismatic, sexy species (looking at you Chris Lowe with your white sharks and Larry Allen with your giant sea bass) while alas, my story of white croaker only drew a few hearty individuals who powered through their hangovers to the last day of the conference.
So why would you spend your time researching white croaker? And maybe even more importantly, why would agencies pay you to research this rather unremarkable fish? Well buckle up buddy, ‘cause here is everything you didn’t know about white croaker and why they may be more important than ever.
White croaker have a variety of creative nicknames including tomcod, kingcod, or my personal favorite the LA River sewer trout. Even though this fish is not a cod or a trout it was once and (arguably) still is an important fishery in southern California. While the commercial fishery of white croaker in the Palos Verdes Shelf area officially ended in 1990, white croaker are still important to many recreational and subsistence fishers in SoCal. These fish are known for being tasty and honestly one of the easiest fish to ever catch on hook and line. Yes, someone somewhere in SoCal is lazily bringing up their line just to ‘check it’ to find that there is indeed a white croaker hanging out on their squid bait.
Apart from the nostalgia of being the first fish many SoCal fishers catch, white croaker are also apparently a rather tasty fish. Would I know if they were tasty? Nope. Ever since I moved back to California white croaker have graced the pages of OEHHA consumption guidelines (officially in 1991) for their high concentrations of DDTs and PCBs. I have never eaten my study species even though I spent 3 years (and counting) working on these fish. But not all people have the luxury to throw back the white croaker in hopes of a better, less contaminated fish. Many subsistence fishers in the LA harbor frequently visit free fishing piers, such as the Cabrillo Pier, in hopes of catching any fish to bring back to their family for dinner. Despite posted advisories and some rather entertaining marketing trying to educate and deter people from consuming large amounts of contaminant ridden fish, sometimes this message just doesn’t ring home.
Ok so people eat these things when they probably shouldn’t because it’s a human health risk. But you could say that about many of the other fish species on the consumption guidelines that are well…a bit more interesting. This is true but missing perhaps one of white croaker’s best kept secrets. They have a superpower. No it’s not flying, or reading minds- it is actually very similar to a totally unrelated species, the canary (which can fly in addition to other amiable qualities). Canaries were once used in coal mines since they are sensitive to dangerous gases, such as methane and carbon monoxide. The canaries would stop singing (and you know… die) when these gases were detected, which acted as a warning to miners to get the heck out of the mine. White croaker do the same thing, minus the instant death thing (though historically some had some pretty ridiculous fin rot and one recently has been found with an impressive tumor). White croaker are an indicator species, much like the canary, for contamination in the marine environment. White croaker just love the same type of sediment that these nasty pollutants, like DDT and PCB, can easily bind to and are susceptible to this kind of pollution. So if you find out where croaker are spending a lot of their time and clean that area up, the fish should be less contaminated (which is good for the people who eat them). This also benefits animals that eat white croaker such as kelp bass and sea lions since less contaminated fish means less contaminants to biomagnify up the food chain. So white croaker really are a super hero for environmental studies by taking one for the team and being sensitive to contamination. And that is why I study white croaker, they are the unsung super heroes that everyone thinks look a little silly.
Affiliation: NASA's Kennedy Space Center
Bonnie is a former member of the CSULB sharklab and studied- you guessed it- white croaker movements. She is now a fisheries biologist at the Kennedy Space Center and is interested in movement and behavior of fish species. Follow Bonnie on twitter @bonnie_ahr.