Natural Perspectives: The wildlife of our waters

Our missing summer seems to have found us. It’s been so hot here that our chickens are laying boiled eggs.

Vic beat the heat this past weekend by taking a pelagic trip with his birding class. They joined members of Sea & Sage Audubon Society on a cruise on the Sea Explorer, one of the vessels operated by the Ocean Institute in Dana Point.

Vic reported that they had a fantastic cruise, with clear skies and glassy seas. The smoothness of the trip made it far easier for Vic and the other leaders to point out birds on the horizon and for the students to get their binoculars onto the birds.

The avian highlight of their trip was a flesh-footed shearwater, a species I had never even heard of. This was the first time that even the most experienced of the trip leaders has seen this species. Flesh-footed shearwaters are medium-sized, narrow-winged, brownish-black birds with light pink feet and pale pink bills with black tips. They spend their lives at sea except during breeding season.

These migratory members of the puffin family forage widely over the Pacific and Indian oceans. They are occasionally seen on the west coast of the U.S. and as far north as British Columbia. The main breeding colonies are on Lord Howe Island in eastern Australia and on the coast of northern New Zealand, as well as a smaller colony off the coast of western Australia.

Like many other species, these shearwaters are in rapid decline. On Lord Howe Island, the amount of suitable habitat has declined by more than 35% since 1978. These shearwaters seem to be suffering the same fate as the much rarer California least terns and Western snowy plovers that breed at Bolsa Chica, Upper Newport Bay and on other Southern California coastal dunes. Development and recreational use of their historic breeding sites has put them at risk.

Urbanization of breeding sites is only one of the major factors in the decline of the flesh-footed shearwaters. These pelagic birds are frequently caught on long-line hooks of fishing vessels. Ingestion of floating plastic is yet another hazard that they face. The Pacific Ocean is becoming filled with miles and miles of floating plastic, a byproduct of our modern world. Vic reported that he was rarely out of sight of Mylar balloons floating on the ocean, and they went halfway to Catalina.

Other threats facing the shearwaters are predation by dogs on their breeding grounds, collisions with automobiles, use of herbicide near their breeding colonies and trampling of their burrows by cattle.

While Vic was out on the ocean, I visited the Long Beach Aquarium of the Pacific with a friend. The lorikeet aviary was closed for renovation, but I really enjoyed the exhibit on world population growth, over-fishing and global warming. The ocean is in trouble, and it’s mostly the fault of us humans and our burgeoning population.

I also enjoyed the shark and stingray touch tank. It was interesting to contrast the silky smooth skin of the rays with the raspy skin of the brownband sharks. Shark Lagoon had the larger, non-pettable sharks like tiger sharks, black-tipped reef sharks and even a hammerhead shark.

Vic and his class also sighted a hammerhead shark. I didn’t know that hammerheads swam off our coast, but apparently they do. There are nine species of hammerhead sharks, with worldwide distribution. The youngsters like to swim near coasts and along the continental shelves.

Hammerhead sharks’ eyes are at each end of the hammer, giving them a really weird appearance, but also providing them with excellent stereo vision. The array of neurosensors in their oddly-shaped heads allow them to pick up the extremely weak electrical signals that are given off by stingrays, their favorite food. They also eat fish such as mackerel, herring and sardines, as well as the occasional invertebrate. They even eat each other.

Three of the nine species are known to be hazardous to humans: great, scalloped and smooth hammerhead sharks. But in general, even these don’t attack. Their mouths are on the bottom of their heads, not the front. They’re adapted to eating stingrays off the bottom, not surfers.

One of the biggest threats facing hammerheads is that they are being caught for their fins. Fishermen catch these sharks, cut off their fins for shark fin soup and toss the hapless shark back into the ocean to die. They are also caught for fertilizer and pet food. Populations of the greater, scalloped and smooth hammerhead sharks declined 90% between 1981 and 2005.

A major international study by the IUCN Shark Specialist Group and published in 2008 indicated that 16 out of 21 shark and ray species are at increased risk of extinction because they are being fished for their fins and meat, or are being caught as by-catch in the fishing industry.

It seems that no matter what large marine species you look at, it’s in decline. The ecosystems of the world are connected, and when we tug on a string of the web in one place, it reverberates in another place. We hope that our efforts to conserve energy and reduce our use of plastic will have a good consequence for the ocean ecosystem.

VIC LEIPZIG and LOU MURRAY are Huntington Beach residents and environmentalists. They can be reached at LMurrayPhD@gmail.com.