Kelpscape

Speed Kills Whales

Along with other passengers aboard the Islander, I watched a threesome of humpback whales in the Santa Barbara channel on Sunday, north of Anacapa and near the shipping lanes.

As the LA Times reports, several environmental groups including the Environmental Defense Center have filed a petition requesting a mandatory 10-knot speed limit within California's national marine sanctuaries, including the Channel Islands sanctuary. Presently, when whales are in the channel, ships are advised of the fact to slow down; but few do.

Ship strikes routinely kill whales, both inside and outside the sanctuaries. Blue, humpback and gray whales visit the sanctuary in significant numbers; many others  occasionally.  The whales may not hear the ships coming; ships have become quieter since the advent of hull shapes that minimize the wake (which, after all, takes energy to produce and so robs power from the ship's engines). Whales have terrific hearing but the channel is a very noisy environment.

The whales tend to congregate near the 200-meter depth contour, as records of whale sightings from the Cascadia Research Collective and Channel Islands Naturalist Corps suggest. There's some suggestion that they feed there; on the other hand, a lot of them seem to be engaged otherwise; the captain suggested that the 3 we saw were mating, for example.

The ships tend to stay pretty well within the shipping lanes (these are on either side of the pink stripe in the maps). That cuts across the 200-meter line at the East end of the channel, where we saw the trio of humpbacks on Sunday. That's definitely the most crowded part, with boats making the hop from Ventura or Oxnard to the islands at their closest approach to the mainland, as well as ships and whales. In principle, ships could travel through the channel more slowly, or take the longer path around the islands.  That would add time to the passage from the Far East, making factories in the Far East less competitive with US manufacturing. That doesn't seem particularly undesirable. 

The people who control the speed of the ships are their owners, most of them in other nations; ships are expensive and the owners are keen to have their investment pay off.  From their standpoint, from a purely economic perspective, faster ships and shorter routes between the same ports pay off faster.

 It would seem to me, the blogger, that big ships should avoid areas crowded with whales and boaters; or at least drive carefully and pay a premium as well.  The cost of futons may increase a little bit; but I'd be glad to pay a little more to give the whales plenty of space for their fun.

 

Ling Cod at Rat Rock

This was (and still is) the biggest ling cod I've ever seen.  At first I thought it was a leopard shark. It was in the marine reserve on the north side of Anacapa, at Rat Rock, relaxing on the bottom under a sea palm.  Despite its protected status in the reserve, it took off after I'd taken only a couple of snaps.

Kelp at Judith Pinnacle

Giant macrocystis kelp kelp at Judith Pinnacle. This pinnacle rises to as shallow as  50 ft, from a surrounding bottom at 120 ft.  Lots of kelp grows atop the pinnacle; in my few dives there I've never seen it reach the surface, although it gets as shallow at 25 ft.  Sometimes the kelp seems to deceive the depth finder on the boat into thinking that the pinnacle gets up that high.  It can be a tricky dive.  I always end up holding onto the kelp as I do the safety stop.

Invertebrates at Judith Pinnacle

Clones of corynactis (a.k.a. strawberry anemones) interspersed with feather-duster worms on the side of a rock atop Judith Pinnacle.

Blue Rockfish at Judith Pinnacle

Hundreds of blue rockfish float above Judith Pinnacle, on the south side of San Miguel Island.  This region is a marine reserve, and doesn't get dived too often.

 

Alternative Universe of the Inverted Kelp

Tasmania has kelp indistinguishable from ours in Southern California -- but populated by boxfish, puffers, and sea dragons. It's sort of an alternative underwater universe:  upside-down, with kelp growing away from our northern-hemisphere ocean surface, but mirroring it in many ways.

When I first visited Australia over 10 years ago, I wondered: Did this strange place, the world's lowest, geologically quietest continent, represent the future of our planet, or its past? After Antarctica (which seems scarcely to count), it's the worlds least fertile, driest, and least populated continent. With extinct volcanoes, nearly-extinct exotic mammals but overabundant cane toads and rabbits, downtrodden aborigines safeguarding Earth's oldest culture, a nation with 1/3 the population of California and 5 excellent newspapers: is this where our planet is going, or a quaint remnant of the prehistoric past?

On my first dive into the Tasmanian kelp forests at Fortescue Bay, just south of Eaglehawk Neck, I realized: this land is a parable, from which we can learn.  The kelp forests contain abalone not too different from ours, although much more plentiful; and sea urchins, including an invasive species that is moving southward along the coast, leaving urchin barrens behind. They have many species of wrasse, where we have just 3; but they have no rockfish, and we found no scuplins. 

Sadly, the Tasmanian kelp forest is nearly gone, replaced by urchin barrens and smaller algae. Just a small patch is left.  It's clearly overfished, even relative to California.  Grab-all nets, basically floating gillnets 50 meters long, catch every creature that tangles in them. A recreational fishing license to set one costs A$50~US$32. On our third day of diving we came across a graball net that had lost its mooring buoys, and drifted for days, ghost-snagging a lobster (or a "cray" as the Aussies more accurately call them) and about 10 fish of every kind, most too small to eat.

On one of my last dives at Cathedral Cove, gliding through caverns covered with yellow zooanthids, I realized that the Tasmanian kelp forest is complete in itself, although it shares its fundamental feature with our forests.  Both are under great stress and may soon perish; but comparison of the two might help to preserve them.

Marine Reserves are Working

Marine reserves at the Channel Islands are producing more and bigger fish, according to a scientific study reported at a special session of the Channel Islands Symposium.  The study used about 1700 fish counts from REEF.org volunteer divers. So far the results are for relatively rapidly-reproducing fish.  Over the next few years, longer-lived, slower-reproducing fish like rockfish should show some beneficial results as well.  It'll be interesting!