If you miss visiting the estuary, its educational programs and learning about our local flora and fauna, there is a way to stay in touch. Lunchtime Live is a live educational show held once a week hosted by Tijuana River National Estuarine Research Reserve Education Specialist Marya Ahmad.
Lunchtime Live on Facebook was launched in response to COVID-19 and Ahmad has lectured on varied topics ranging from cliff swallows to orb weaver spiders. The half an hour lectures are very interesting and attendees have the opportunity to ask questions and post comments during the live show. The videos, which are recorded, can also be watched later.
For instance this past Tuesday, Ahmad filmed from the end of north Mc Coy trail. The topic she discussed was “Who Are the Jumping Torpedoes of Our Coastal Waters?”
Ahmad gave a very informative talk. She spoke of those torpedo-shaped fish, the striped mullets, that are common in the estuary channels. They are usually about 1 and a half feet long, however, the largest one has been recorded at 3 ft in length. Ahmad said these fish live about five years, although there have been reports that some had lived 13-15 years, and reach maturity at 2 or 3 years old. Mullets travel in schools and are bottom feeders, eating dead material on the bottom as well as plankton and micro invertebrates. Even though they are large they don’t eat small fish, “but more the microscopic end of things,” Ahmad said.
Mullets travel in school when they spawn. Spawning for them depends on the time of year and has to do with the temperature of the water. Mullets lay between half a million to a couple of million eggs at a time. Males fertilize them and once fertilized, the eggs only take just 48 hours to hatch. Of course not all of the eggs become adult striped mullets. The purpose of the females spawning so many eggs is that they provide food for other aquatic species.
Ahmad showed different photos of mullets during the show, whose Latin name is Mugil cephalus. Mullets are native to this area and generally live around the world in coastal waters in tropical and subtropical areas in temperate regions both in in river mouths, and coastal waters. Ahmad described a mullet as an average looking fish of silver color, torpedo-like shape, with large eyes, dorsal fins, a small mouth and striped pattern on its body. She elicited questions and comments from viewers which she read aloud to share with everyone. Mullets can be seen at edge of piers, bridges and channels and can be easily spotted if swimming near the surface because they are relatively large.
Mullets jump completely out of the water and do a flop to get back in. Ahmad said nobody knows for sure why mullets jump out of the water. Some theories are they do so because they are being chased by a bigger fish or sea lion, especially offshore, but in the calm water of the estuary there wouldn’t seem to be a reason. Plus they are one of the larger fish. “No real definitive answer,” she said.
A viewer suggested they jump to get more oxygen. Ahmad said mullets have the ability to breath straight from the air not only from the gills, and it is possible if the oxygen is low and if the water is warmer, they could jump for extra oxygen. Another possibility is that mullets jump to get parasites off of them.
Mullets are commercially important with aquacultures in Asian countries and Venezuela. These fish seem to do well in a variety of salinity up to 75 parts per thousand and have been introduced in the Salton Sea. Mullets are a tasty treat for ospreys and can be often seen in their talons being carried off to their nests.
“Striped mullets make an excellent meal for ospreys,” she said. Ahmad pointed out that there are many osprey nests around including the Imperial Beach ball park, private yards and along the Silver Strand. Typically they don’t like water less than 60 degrees and in California they live all the way up to San Francisco Bay.
The stories and facts on the mullets is just one of the interesting topics on Lunchtime Live. Connect with the Tijuana Estuary to learn more about why it is such a gem of Imperial Beach.
Lunchtime Live on Facebook is every Tuesday at noon. For more information log on Facebook.com/ Tijuana Estuary (Tijuana River National Estuarine Reserve)