Filmmaker's Journal: mackeral form massive aquatic highways

This past weekend, me and my good friend, photographer Budd Riker, went over to Catalina Island, off of Southern California, for a couple of dives. I needed to test out a new lens for my Amphibicam EX3 underwater housing - a great housing for a great video camera (the Sony PMW-EX3). I'm fortunate to have one of the few housings currently available in the U.S.

To make it quick and easy, Budd and I took the fast Catalina Express boat to the main island city of Avalon to dive at the popular Underwater Park at the city's famous Casino Point. With the park being a great place to conduct scuba diving classes, the sea wall at the point is typically lined with dive bags and assorted gear - and this day was no exception. It was crawling with divers.

But the Underwater Park seems to handle the diver pressure pretty well. It's a protected zone; you can't remove anything from the water except trash, no souvenir empty shells, no rocks, nothing. And because there is no fishing or hunting of any kind, it becomes a sort of refuge for many fish. Large calico bass will hang out in the flowing kelp and California sheephead will cruise by, seemingly aware that they are free from harm within the park's borders.

From above, we noticed that the visibility looked clear and promising, with a slight current moving through and bending the long stalks of kelp over to one side. Upon entering the water, our surface observation was confirmed: exceptional visibility for this location with an almost uncharacteristic blue tint to the water.

As we settled to the bottom, we were greeted by a large school of young mackeral. When they amass along the rocky shoreline, it's quite a sight to see. You have probably seen pictures or films of large schools of anchovies or other fish, congregating in immense balls. Well, for these mackeral, they instead form an undulating mass that weaves its way around the rocks and kelp like some elaborate network of aquatic highways with various underpasses, overpasses, turnoffs and junctions. Thousands of fish emulating California rush hour traffic (and when the current picks up, they come to a stop, hovering - just like our daily battle with gridlock!).

It's believed that a fish's lateral line - a sensory organ along the length of its body that can detect changes in water pressure - is what enables fish to maintain spacing and move en masse in schools. Each fish, when swimming, produces a pressure wave that the surrounding fish can sense and with that a collective sense of order and movement is established.

The mackeral continued to entertain us and gave us plenty of subject matter to film or photograph. They would double back, seeming to enjoy the security of the Underwater Park and only occasionally spreading out in large circles to give a possible hungry Calico Bass a wide berth, or darting about suddenly when a sea lion would make a quick pass.

Just an overall great day at one of Southern California's ocean treasures: a simple, little underwater oasis, able to withstand man's curiosity. Hopefully, with each new diver that completes their training at Catalina's Underwater Park, a conscientious ocean conservationist is born.

Video clips of schooling mackeral will be up soon in RTSea's stock footage library.

Humboldt Squid: the "red demon" moves into Southern California

Like something from Disney's Twenty Thousand Leagues Under the Sea, the humboldt squid is a formidable predator typically found in deep Pacific waters off of Mexico and Central America. Reaching up to five feet in length and as much as 100 pounds, it is fast and aggressive with a voracious appetite.

And it is beginning to appear in shallower water off of Southern California. In San Diego, during night dives, scuba divers are encountering groups of humboldt squid, and several have moved too close into the shallows and been washed up on the beach.

According to a recent AP news report,

"Research suggests the squid may have established a year-round population off California at depths of 300 to 650 feet, said Nigella Hillgarth, executive director of the Birch Aquarium at Scripps Institution of Oceanography. Divers this summer have been encountering them at about 60 to 80 feet down, they said. No one knows how many squid are in the shallow waters, but one biologist estimated they could number in the hundreds, or possibly thousands.

'Usually where there's one squid, there's a lot of squid, so I would assume that there's a good number,' said John Hyde, a biologist with the National Marine Fisheries Service in San Diego."

Scientists are not sure why the squid have moved further north or are entering shallower waters. Explanations range from global warming to loss of prey to a reduction of natural predators. On this last point, I have read studies that have explained the bio-dispersion of various species based on the predators that feed upon them. When the predators are gone, then the species in question is no longer "corralled" as it normally would and changes in bio-dispersion or migrations can occur. In the case of humboldt squid, sharks are one of its key predators.

Whatever the explanation for the squid's movement north, there is reason for some concern. They can pose a serious risk to unsuspecting divers and their voracious appetites can severely impact local fisheries. Scott Cassell, CEO of the Undersea Voyager Project, who has spent many years studying and filming humboldt squid, recently told me that in his studies he had predicted the potential for this danger as much as ten years ago.

Another possible example of the ramifications either climate change, overfishing, or loss of apex predators - or all of the above.

Care for a calamari ring the size of your dinner plate?