October 24, 2007

Invasive Round Gobies off the Oshawa / Bomanville shoreline (Lake Ontario)

Winston Stairs, one of the regular readers of this site, recently submitted this report to me. He previously reported on Bloody Red Shrimp.

If my research is accurate, my report (below) is the first to document round gobies* off the Oshawa / Bomanville shoreline. Previous reported locations were Hamilton and Picton, Ontario.

* - Round Gobies (Neogobius melanostomus) are a non-indigenous species of fish from the Baltic region (Europe) introduced into the Great Lakes basin back in 1990. They are believed to have come in by way of ballast water on ships entering the Great Lakes system through the St. Lawrence River. They have few natural predators and are a stressor to the ecosystem by competing for food stores of native species of fish (bass, perch, pickerel, etc.).

Subject: Neogobius - minor report - 10/21/2007

Regrettably, conditions were less than optimal today for conducting a full and complete survey of Neogobius melanostomus on the wreck of the Juno off Bomanville shore.

Horizontal visibility was estimated at 4'-5' (1.2m) and aquatic (piscine) life was virtually non-existent - one sizeable small mouth bass (Micropterus dolomieu) and 5 small (5-6cm) round gobies (N. melanostomus).

In addition, the density of suspended particulate matter made photography virtually impossible due to backscatter from the flash.

Having seen many round gobies on the Juno in past, I had hoped to run a 10m transect line and conduct population counts within a 1m quadrat along the line. However, seeing the conditions and scarcity of gobies I opted to provide a brief, informal report.

Date: October 21, 2007

Time: 09:50 - 10:30 EDT (13:50 - 14:30 UTC)

Location: Lake Ontario, wreck of 'The Juno', off Bomanville shore (GPS 43 53.157 / W 78 40.491)

Depth: 12' (3.65m) max., 10' (3.04m) average

Temp: 52 deg F (11.1 deg C) at depth

Visibility: 5' (1.5m) horizontal est. (Vertical transparency using Secchi disk not conducted)

Gobies Present: Yes

Number: 5

Length: 5-6cm avg.

Benthic Substrate: Predominately sand (fine grain) with rocky inclusions (avg. stone size - 4cm dia.)

Spatial Distribution of Neogobius nests: None identified

Estimated Density of Neogobius nests/cavities: No findings

Nearest neighbour distribution of nests: None identified

Size of nest opening: No findings

Size of nest guarding male: None present

Surface area of nest covered with eggs: No findings

Posted by Dida at 10:18 AM

June 2, 2007

Sometimes When You Sweat The Small Stuff The Big Stuff Swims Right Up To You

by Jonathan Lavan
I have been diving and exploring the undersea realm for more then twenty years. I thought I had just about seen it all. About five years ago I starting diving with the Reef Environmental Education Foundation (REEF). This non-profit organization dives the world counting fish and doing other research to aid like-minded scientific and environmental organizations to assess the current health of different reefs and regions.

A group of us were diving off Key Biscayne National Park just north of Key Largo, Florida. Nearly thirty years ago, in 1979, a researcher named Jim Tilmant dived several of the surrounding reefs and presented his findings to the National Park Service. Fast forward to 2007: The National Park Service, with help from The National Marine Fisheries Service (out of their Miami office), decides to replicate his studies to see what changes have occurred. The NPS hired REEF to do a companion study at sites deeper and shallower (east and west) of the original Tilmant sites. Our job at each site was to do a general fish count according to our established criteria as well as measure the length of all groupers and snappers seen. Believe me, it's not easy to get them to hold the ruler. I was the photographer on staff so I spent most of my time on each dive in a ten foot square area finding tiny little blennies and gobies (see picture above) and, over all, let the fish come to me.

By the third day of four we were getting a bit frustrated as the weather has been less then cooperative. The forty-five minute to one hour boat ride to each site got rougher as the days passed. Between the tanks and the boat rides our lower backs were taking a pounding. We finally had to scrub day four altogether because it was simply too rough. That meant we would have to dip into day five, our weather day, and hope for the best.

The weather on our final day, Friday, March 23rd, held together well. We had a good first dive and we were happy in the fact that we would be able to complete our assignment. The boat was sitting in the shelter of a dive site called Long Reef. We were doing our surface interval and enjoying our lunch when the captain noticed a very large caudal fin sticking out of the water about 30 yards off the bow. Whale sharks are very rare in the Florida Keys so we were all highly skeptical, but what else could it be? The captain eased the boat over to the animal. Fortunately I only had my wetsuit half off and my camera is always at the ready. I eased over the side and managed to get some shots before the monster fish made a few small twitches of that mammoth tail and was gone. I judged it to be about thirty-five feet long, as the cobia (Rachycentron canadum) swimming about it were each about three feet long. I spent a week in Honduras looking for whale sharks during their breeding season and saw nary a one. This was, for me, a once-in-a-lifetime experience. I think from now on when I'm diving I'll pull my head out of the cracks and crevices now and again and look up and around. You never know what gentle giants might be swimming by.

If you are interested in seeing more of my photos please see my dive blog: Underpressure World

If you are interested in finding out more about the Reef Environmental Education Foundation please go to their website.

Thanks Jonathan- also jlavan @ mbayaq.org

Posted by Dida at 11:24 PM

September 21, 2006

Fort Ross, California Abalone and Urchin Survey

by Greg Holzer


Sea Urchin and Abalone transect
surveys in northern California

Photo Credit: Shannon Fitzgerald.
The California Department of Fish and Game (DFG), leads red abalone and red sea urchin density surveys each year at designated sites in northern California. The survey teams include divers from the department, Bodega Marine Laboratory (BML), Humboldt State, and volunteer AAUS-certified scientific divers. In 2006, the dive surveys were lead by Dr. Laura Rogers-Bennett and were conducted at three sites: Timber Cove, Fort Ross, and Van Damme State Park. At two of the sites, density and size frequency data were collected at multiple depths, while at Van Damme the sixth year of recruitment monitoring was completed, along with the start of a large-scale red abalone tagging program. As one of the two volunteer AAUS-certified scientific divers, I was very pleased to be able to join in on the Fort Ross surveys scheduled for September 11-15, 2006. The dive teams are supported by the department’s Wildlife protection patrol boats, Captains, and mates. Funding for many of these surveys is made possible by the recreational abalone fishing stamp funds and the Recreational Abalone Advisory Committee.

Survey sites range along the Sonoma and Mendocino County coastlines. Protocols involve pairs of divers laying a 30-meter transect tape on a specific heading, then swimming along the transect while completing a datasheet, and tabulating measurements and quantities of selected species that occur within one meter on each side of the tape. The starting point of each transect is identified with its GPS coordinates. Surveyed species include red, flat, and pinto abalone as well as red and purple sea urchins. In addition, selected algal species and certain associated species (e.g., bat stars), as well as notes on seafloor composition are recorded. Typically, it takes between 30 and 60 minutes to complete a transect, depending on the number of animals and general sea conditions, which can occasionally get interesting in some of the shallower spots, with kelp and an energetic surge.

The divers had as their base of operations the DFG’s enforcement vessel P/B Marlin, a 54-foot aluminum catamaran, skippered by Captain Keith Long, with Warden Ed Morton as crew. The Marlin is equipped with a 17-foot Rigid Hull Inflatable and electric/hydraulic hoist for launching it. In addition, BML supplied a 14-ft. Zodiac with a 25-horse motor. The Marlin is a very capable diving platform, and with this equipment combination, we were able to field four teams of divers to lay and survey twelve, 30-meter transects each of the three days. U.C. Santa Cruz provided a portable compressor so that empty tanks could be filled during diving operations, minimizing the number of tanks that had to be handled, and preventing the need to load and unload tanks during the cruise.

The cruise plan was to depart Spud Point Marina in Bodega Bay about 0800 each day, anchor near the site, and launch divers in the Zodiacs with tanks for two morning dives. We would return to the Marlin for lunch, a bit of rest, and then finish with one afternoon dive. The Marlin returned to the marina each evening. Lunches were provided (and prepared) by the DFG crew (hamburgers and grilled chicken, with the usual “accessories”), and there was a good stock of snacks and drinks, as well.

The results from the Fort Ross survey along 37 transects showed that we encountered 1,252 red abalone, 2 flat abalone (pebbly mantle) and 3 pinto abalone (bright yellow tentacles in the respiratory pores). In addition, we saw 947 red sea urchins and 2 purple sea urchins, not to mention the zillions of bat and ochre stars. Interestingly, the flat abalone were at the shallower transects while the pintos were in deeper water and on the very tops of boulders, which is typical for this species. Not many divers know that we have three species of abalone on the north coast, not to mention the occasional black abalone in the shallow and intertidal habitats. Water temperatures for this cruise were in the low to mid 50F range, and visibility varied from about five feet in turbulent areas, to near 25 feet on some deeper transects.

It’s worth noting that this cruise was originally scheduled for five days, September 11-15. As is typical of this area, though, wind and seas picked up after a few days, safe diving couldn’t be conducted, and Thursday and Friday had to be cancelled. However, due to the good weather Monday through Wednesday, and the number of divers available, we were able to complete the 36 scheduled transects (plus a spare one), and finish all work planned at the Ft. Ross site.

With that last paragraph as segue, I’ll add that there is a continuing need for divers for this work each year, from around mid August to late September. If you’re interested in this sort of research, and are AAUS-certified, DFG would like to hear from you. You can email Dr. Laura Rogers-Bennett.

Posted by Dida at 3:27 PM

August 8, 2006

"State of U.S. Coral Reefs" Reports for Libraries, Labs

from Coral_list 8 August 2006:

In August 2005, NOAA announced the availability of a report entitled: The State of Coral Reef Ecosystems of the United States and Pacific Freely Associated States: 2005. This report represents an initial effort to determine the present condition of shallow water coral reef ecosystems based on quantitative results of assessment and monitoring activities conducted by Federal, State, Territory, Commonwealth, non-governmental, private, and academic partners. Production of the report was led by NOAA in close collaboration with teams of experts that authored chapters on the condition of coral reef ecosystems in each of 14 jurisdictions. PDFs of the report chapters are available for free here.

Jenny Waddel, who posted this, is seeking assitance "in placing the remaining printed copies of the report in University libraries and marine labs, where they can be accessed by many. If you know of an academic library or marine lab that would like a copy of the report, please ask them to send a formal request for the printed report to CoralReport2005 so that we can make the information as widely available as possible."

Posted by Dida at 1:47 PM

January 3, 2006

The Octopus Tattoo

original posting 2005-11-2

I floated 55 ft below the surface of the Strait of Juan de Fuca, sketching a beige sculpin that I did not recognize, when I saw a strand of red kelp drifting by. I noticed a line of white suckers running along it. Next something heavy dumped on my head. Another tentacle with delicate suckers curled in from below and pulled my mask away from my face, flooding it. I felt other tentacles squeeze the right side of my face and pull on my hood. I'd last seen my dive buddy peering into a crevice -- he didn't appear, although I turned around a couple times hoping he might take a photo. I tried to brush the octopus off my head, but he squeezed all the tighter.

When the octopus tried to pull my regulator out, the aggressive response took over. "OK, buddy, let's see how you like breathing air!" I drifted to the surface, maintaining the <60 ft/min safe ascent rate, and clearing my mask a couple of times on the way up to check. I surfaced with unusual headgear and saw the dive boat nearby. The octopus actually continued to squeeze my head, but finally my efforts to brush him off persuaded him to leave. I cleared the mask again and looked down to see him swimming away; only about 2.5 ft long. When the boat captain finally spotted me, he seemed not to believe my shouted explanation, but directed me to my buddy's bubbles. Once near the bottom, I checked off: 1 Giant Pacific Octopus.

I had always been curious about northwest diving, and the REEF fish-counting trip seemed like an ideal opportunity to try it. The diving was in the Olympic Coast National Marine Sanctuary, off the Makah reservation at the northwest corner of Washington State. REEF paid for the boat and lodging; we were responsible for transport, food, and air fills. Conditions were excellent: that meant flat water, sunshine, moderate to strong current, and 44 to 47 F water. My dive buddy, Stan Kurowski, wore a neoprene drysuit filled with argon (lower thermal conductivity than air) and inflatable dry gloves. With enough fleece underneath, my trilam drysuit seemed up to the cold, although my wet gloves were chilly: after 20 min my hands began to sting, and after an hour they really complained! I'd torn a wrist seal the day before meeting the octopus; Stan and Doug Biffard glued a seal from one of Stan's old dry gloves over the old one, saving my trip.

The above- and underwater landscape is volcanic, with big boulders, walls, and crevices. Sea palms and single-bladder nereocystis dominated the kelp forests. Although diversity of fish is less than Southern California, black rockfish, kelp greenlings, and ling cod were relatively plentiful and often huge. In the last minutes of my last dive there, I saw a wolf eel with a head the size of a dinner plate. Sculpins were far more diverse than in California, although usually hard to spot and identify. Small nudibranchs and giant plumose anemones were common. We saw many whales swim nearby above water, none below, although on a couple of occasions the people on the boat saw them blow less than 15 ft from our bubbles. The water was often thick with large and small krill, and in places the visibility was consequently less than a foot, although more commonly about 40 feet.

We took advantage of the great conditions to dive off Tattoosh Island, just off the northwest corner of Washington State, and even "around the corner" on the Pacific Coast of Washington State. Captain Troy Sterrenburg maneuvered his dive boat "Dash" skillfully through the live-boat drift dives, necessitated by changeable and sometimes stiff currents. The tides set our dive sites and times. Her stern ladder and jet drives gave us confidence in safe exits.

The Makah were celebrating Makah Days during our trip: the occasion for a parade, fireworks, and contests for several age categories of Ms. Makah. Posters featured ancestries of the candidates. Sanctuary Education Specialist Greg McCormack arranged some special events for us: we watched teenagers perform traditional dances at the gym, and an older Makah woman told us about earlier days, and the advent of schools and roads. The Makah were skilled hunters, and 8-man teams of specialists went after whales. Things are harder now, with less fishing, although I found some excellent smoked salmon.

When I climbed on the boat after meeting the octopus, Capt. Tory Sterrenburg laughed and reached for his camera. Small red hickeys covered a third of my face. The giant pacific octopus I met was one of two we counted; apparently the males are quite territorial, and will attack encroachers. The one I encountered was the most aggressive anyone on the boat had heard of. Trip leader Brice Semmens snapped a few photos.

I'd heard about the trip through REEF's AAT (Advanced Assessment Team) listserv. To become a subscriber, you must complete at least 50 REEF fish counts, and take the Level 4 or 5 multiple-choice examination on fish identification. REEF runs quite a few trips, with varying destination and costs; they provide opportunities for diving in unusual places, meeting interesting people, and -- yes! -- new tattoos.

See BlackCormorant.net for more photos from the trip.

Posted by Carl Gwinn at 6:41 PM | TrackBack

August 10, 2005

Wrecks as Bioclutter

When my sister and I were children, we collected shells from the bottom of the ocean in Kentucky: the Ordovician ocean. Thick masses of crinoids, bryozoans and brachiopods surface there, in reefs of half-billion-year old limestone. I now know that those animals represented a sudden departure (during the immediately preceding Cambrian period) from previous, much simpler forms. As a diver, I see their nieces and nephews on the ocean bottom today; and I'm a slightly more distant relation myself.

The seemingly infinite amounts of plastic and aluminum we produce, as well as the extinction of so many other species, are now forming a geological layer that will certainly bemuse intelligences a billion years hence, should any visit this planet. Our period may represent a similar dramatic explosion of paleontological forms, perhaps followed by some more measured further evolution.

Recently I had the opportunity to see a few of these fossils in the process of formation in California's Channel Islands National Marine Sanctuary (CINMS), on a cruise to monitor archaeological resources aboard the R/V Shearwater. Trip leaders were Coastal Maritime Archaeology Resources (CMAR) President Mark Norder and CINMS Cultural Resources Coordinator Robert Schwemmer. We viewed 3 wrecks, of different states of age and preservation:fossils in the process of forming, or failing to form.

A Grumman Avenger, one of 2 torpedo bombers that collided and crashed on a training mission during WWII, lies at 125 feet depth in the channel. Careful work by Captain Terrence Shinn found a small bump by depth sounder. Mark and Robert dropped a line at the spot, and made the first dive on the wreck. They reported the airplane in good shape, though degraded from previous visits. With CINMS Research Coordinator Sarah Fangman, I dropped quickly down the marker line, then swam upcurrent along the trail that the anchor had dragged through the brittle stars in the sand. The light airplane's skin is peeling away as seawater dissolves the aluminum. In the brief time before our dive computers demanded that we ascend, we photographed and videoed the wreck. Something, probably a boat anchor, had torn off the canopy since the previous survey a year earlier. The engine had dropped deeper into the sand. This fossil seems unlikely to make it to its billionth birthday.

The majority of our dives were on the Winfield Scott. This passenger vessel, originally built to carry 49ers to the California goldfields, plowed into Anacapa Island in a thick fog in 1853. The crew and passengers all survived, as did the valuable cargo including gold bullion. Most of the passengers had to stay in Frenchy's cove several days while the rescue ship dropped the gold off in San Francisco before returning for them. Despite the age of the wreck, a surprising amount has survived. Big sections of the paddle wheels have become encrusted with coralline algae. The line "of his bones are coral made" drifted through my head. With Ranger Ian Williams of the National Park Service, I tested the reliability of underwater surveys, by repeated measurements. I found it an exhausting and disorienting task to swim the tape between benchmarks, like some schoolyard game gone too far. A huge piston lies on the sea floor: the ship's engine developed a pressure of only 17 inches of water, so gigantic pistons were needed to yield useful power. Development of stronger steel has already relegated these anatomical features to evolutionary history. But, aided by the coralline algae, the bones of this creature may survive at least a few more centuries.

On a Sunday of perfect weather we dived on the Aggi, a sailing ship that survived into the age of steam and steel, as a low-cost, low-speed transport. While the Aggi was being towed to Panama in 1915, a severe storm forced the tow rope to be cut. The Aggi drifted ashore at Talcott Shoals on Santa Rosa, where she became the object of battles over salvage, and a convenient set for films with nautical themes. Robert Schwemmer might smile and call the thick growth of kelp "bioclutter." Underneath, much of the wreck remains. Her structure forms much of the bottom in that particular area, with occasionally recognizable parts of masts or engines.

Already at an evolutionary dead end during her life, she has a good chance for a long afterlife.

Posted by Carl Gwinn at 4:01 PM | Comments (1)

August 9, 2005

Report from the ChanneI Islands, S. Calif: Tending the Eelgrass Garden

(first posted Feb. 2005) After the pounding 2-hour trip across the Channel on the 26-ft "Magic," we anchor at Frenchy's Cove and quickly don scuba gear. The water is so clear we see the gray silty bottom and, yes, even a float at one end of the transect Jessie Altstatt set up 2 years ago. Jessie, Penny Owens, Brian Hall and I are here to check on eelgrass that Jessie and many Santa Barbara Channelkeeper volunteers have replanted here. Once, the bottom of this cove was covered with eelgrass, but a freak boom in white sea urchins in the mid 1980's wiped it out. Seeking to restore the eelgrass bed, Chanelkeeper first set plants here in spring of 2002 and has been returning nearly every month since to check on them.

Eelgrass beds may be important nurseries for fish and other marine
creatures, and in fact are protected by law as Essential Fish Habitat. Eelgrass is not an alga, but is a flowering plant (one of only 4 marine plant species in our region); as you might imagine, pollination is difficult underwater and seeds rarely germinate. Like mint or iris, eelgrass spreads via rhizomes: tough roots from which genetically-identical individual shoots and leaves sprout. Eelgrass may spread to other areas via individual plants torn up by storms, a few of which might land in favorable habitat.

Last year, with the plan to create a new patch of eelgrass, we drove the Magic to Smuggler's Cove on Santa Cruz and (with permission from several agencies including Fish and Game and the Channel Islands National Marine Sanctuary) uprooted 100 plants. Using dive knives, we cut plants with as much rhizome as possible from the dense mat of rhizomes under the sand. We shoved the plants into goody bags before they could float off. The hard work reminded me of how I'd strained my back tearing up mint roots in a home herb garden. We then drove to Frenchy's and replanted them on the next dive, fastening them to the seabed with inverted U's of coathanger (actually, baling wire). Over the years, Channelkeeper volunteers tried different planting patterns: a long row (marked by the transect and floats), open circles, and dense patches. For this new bed, we spaced the plants evenly about a foot apart in a grid.

Now, a year later, we roll off the Magic. Jessie and Penny carry bags of plastic spoons, Brian and I cameras. At 35 ft the bottom is beige silt, covered with brittle stars. Curious pikeblennies peer from empty worm tubes. It's rare to see these Orangethroat Pikeblennies north of Mexican waters, and it was a special treat on this dive. We find 3 lonely eelgrass plants, now sagging under the weight of brittle stars, the only remnant of the hundreds planted along the transect. Brian and I shoot photos and then follow Jessie and Penny toward shallower water.

In 20 ft the replanted eelgrass is flourishing. Some of the denser beds now have several times the 100 individuals originally planted. New patches are springing up nearby. Jessie and Penny count them by placing a spoon next to each plant, then gathering the spoons and arranging them in rows: mathematics is harder under water and every little bit helps! They run out of spoons: too many plants to count exactly. I see a juvenile giant kelpfish in one small clump, with another trying to drive it away. A third juvenile keeps watch from a nearby clump. Brian counts seven sarcastic fringeheads; perhaps objecting to the spoon Penny placed nearby, one bites her thumb and won't let go. Predatory crabs lurk in the shade. Tiny snails cover many blades: they are microcarnivores, cleaning the blades of bryozoans and other life growing on them. The replanted eelgrass is flourishing, and creating a welcome home for a host of young marine creatures.

Channelkeeper is again accepting applications for volunteer divers- email jessie @ sbck.org if you are interested.

Posted by Carl Gwinn at 6:45 AM