Many Lobsters

Warning, this is about horses — terrestrial mammals, yes. But as you may know, cetaceans did come from an ungulate lineage. So settle down kids.

I wanted to tell you all a little bit about my sister’s upcoming epic journey.

On May 25, my sister, Samantha, embarked on a 28-day journey across Nevada on horseback.

Why you ask?

Because no one ever has!

This will be the first solo equestrian ride along the Nevada portion of the American Discovery Trail, the coast-to-coast trail across the United Stated from Point Reyes National Seashore in California to the Delmarva Peninsula in Delaware.

The American Discovery Trail cuts across Nevada in nine segments. It spans 496 miles across isolated backcountry wilderness. Check out the trail on the map below.

In March my MS211 class (Ecology of Marine Turtles, Birds and Mammals) at Moss Landing Marine Laboratories climbed onto a small inflatable boat, pointed offshore, and ran a half mile obstacle course through rocks, waves, and seals to Año Nuevo Island.

This tiny boat (named Dragon Rojo!) carried us to the island. About an eight-minute boat ride though, so not bad. Photo from Oikonos.org.

Last Monday, I bussed it to Santa Barbara then hopped a train to San Diego. One night in a hotel and an overpriced taxi ride later, and I was laying eyes on the R/V Point Sur for the first time since November 29, 2012, on it’s way back from its 17,000 mile round-trip journey to Palmer Station in Antarctica.

Most of my posts tend to reflect my love of marine mammals, specifically the large, “charismatic whales” as they are oft referred to.

But I wanted to tell you about one of my day jobs. [As if grad students have all this time in-between taking classes and working on their thesis. But I digress … ]

I work for a marine engineering company in Santa Cruz, doing coastal engineering. Or, what we tell the general public: we play with mud.

Coastal engineering is a sector within civil engineering. This means companies hire us to help them with harbor design and construction; beach nourishment and erosion studies; wave modeling and forecasting, sediment transport modeling; and dredging and pile driving monitoring; among many others.

Monitoring the dredgers in the Moss Landing harbor.

A few Sundays ago — Super Bowl Sunday, in fact — I took a three-hour walk along the beach at Fort Ord in Monterey, CA with Don Glasco, a systems engineer and former cartographer.

This wasn’t a leisurely pursuit, but my volunteer service to the Sanctuary Integrated Monitoring Network’s (SIMoN) Coastal Ocean Mammal and Bird Education and Research Surveys, also known as Beach COMBERS.

I meet Don at Fort Ord Dunes State Park in Marina around 9 a.m. After downing the last of my coffee, we head out into the foggy morning.

Don Glasco referring to the almighty bird book to identify an unknown species by its toes.

This summer I hopped on a plane, flying 29 hours one way (via Paris — ooh la la) over a period of three days to spend nearly a month on the island of Madagascar working on my pilot study.

Rocky coastline in Madagascar.

Madagascar, a former French colony until 1960, is the fourth largest island in the world. Don’t let it fool you. It looks so tiny next to Africa, but it has 44 percent more area than California, and boasts more than 4,800 km of coastline.

Most of the country’s export revenue comes from textiles, fish/shellfish, vanilla, and cloves. Newer sources of income include tourism, agriculture, and extracted materials (titanium ore, chromite, coal, iron, cobalt, copper and nickel). Madagascar provides half of the world’s supply of sapphires! But with a GDP of around $20 billion, The Economist rated Madagascar as the worst economy in 2011. Most of Madagascar’s inhabitants are subsistence livers, meaning they live off of what they can grow or catch.

Local fisherman spear hunting for crabs.

One hundred and forty two new species were discovered last year. Four of those were deep-sea shark species discovered by Moss Landing Marine Laboratories’ Dr. David Ebert and his colleagues. Their findings, as well as some interesting facts about the sharks, were featured in National Geographic among the new species found in 2011. You can read about it here:

I am heading to Fiji to do this.

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OK not really. I wish. Instead, I am so deep in grad school that I must take three weeks off to catch up. So I apologize faithful readers. If I play my cards right, I might get to go to Madagascar though, so stay tuned. 

In the mean time, here are some cool blogs to check out:

BlogFish: http://blogfishx.blogspot.com/

The Drop in at Moss Landing: http://mlmlblog.wordpress.com/

The Echinoblog: http://echinoblog.blogspot.com/

And of course, ZooBorns: http://www.zooborns.com/zooborns/

There is a really neat technique that scientists can use to calculate the body size of whales. Marine Mammal Science published an article called Correlation between body length and fluke width in humpback whales, Megaptera novaeangliae. The researchers were from Cornell Lab of Ornithology and Instituto Baleia Jubatte.

It's usually pretty difficult to determine whale length and size. You can't just lift a whale out of the ocean and whip out your tape measure. But it's important to determine body length and size, especially to determine mating success, among other things.

An interesting indirect method can be used. It involves a correlation between interpulse intervals of clicks and the size of the sound production organ. But according to the authors, there was a large amount of uncertainty with that indirect method; variations with depth for example.

However, direct measurement of body parts at the surface correlate will the total body length with less error than the indirect methods. One method uses the distance between the dorsal fin and the blowhole. Another, simpler method, uses fluke width measurements to determine body length.

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The researchers obtained measurements from southern hemisphere humpbacks a well as stranded whales from Brazil, assuming their flukes were intact. They used three generalized linear regression models based on sex differentiation to determine the best model to use.

The resulting model was:

Estimated Body Length (BL) = 0.77226 + 2.89694 X Estimated Fluke Width (FW)

The researchers found that bigger animals tend to have proportionately wider flukes. Wider flukes allow for quicker maneuverability, as seen in humpbacks.

Interestingly, researchers found that the male escorts to female humpbacks and their calves showed the largest or second largest in the group. Additionally, males tend to associate with larger females because they give birth to larger calves. All of that points to sexual selection toward bigger individuals, which in turn may be related to fighting ability or survivorship.

Minke whales (Balaenoptera acutorostrata) belong to the order Cetacea, suborder Mysticeti, family Balaenopteridae (the 'rorquals'). (1) As baleen whales, they are larger than the toothed whales and have baleen — comb teeth made of a protein called keratin. However, the minke is one of the smallest of the great whales. (2) According to The Pacific Wildlife Foundation, they are second only to the pygmy right whale. (4)

The Minke was named for an 18th-century Norwegian whaler who was known for his rule breaking; he often hunted larger and other species than allowed. (7)

There are two species of minke whale and a third scientifically unrecognized group. (2) It wasn't until the 1990s when scientists began to recognize more than one species of minke whale. (6) The two recognized species are the northern or common minke whale (Balaenoptera acutorostrata) and the Antarctic or southern minke whale (Balaenoptera bonaerensis). (2) The dwarf minke is included in the same species as the northern minke whale. The dwarf minke is found off Australia, South America, South Africa and the South Pacific. (4) There has also been talk of the discovery of a hybrid minke whale in Iceland.

According to Jon Stern, Ph.D., the Antarctic minke whale is very genetically different from the northern minke whale.

The Antarctic minke lacks the white flipper band and is larger than the northern minke whale. Antarctic minkes have 200 to 300 baleen plates on each side of their mouth and 22-38 ventral pleats that expand for feeding. The baleen coloring is white on the left and right sides and grey in the middle. (2)

The northern and dwarf minkes have stripes on their flippers. They have 230 to 360 cream-colored baleen plates on each side of their mouth and 50 to 70 ventral pleats.

Dwarf minke whales are smaller, however. Their baleen plates have a thin black border and they have a bright white patch on the upper part of their pectoral fin and a half-collar that wraps around their head toward their throat. (2)

Dr. Stern currently studies minke whales in the Northeast Pacific Ocean. He has conducted research on killer, pilot, fin, humpback and gray whales, as well as bottlenose dolphins. (3)

According to him, there's no such thing as a minke whale. He of course is getting at the fact that there are a number of groups (also called stocks for management purposes) of minke whales across the globe. This includes 150,000 in the northern Atlantic; 25,000 in the North West Pacific; 350,000 in the southern hemisphere; and 7,000 in Japan (aka J-stock). In the west coast of the United States from Oregon to California there are an estimated 495 to 806. Other estimates tend to be more optimistic. However, it is difficult to get actual counts due to their elusive nature.

Like all baleen whales, minkes have two blowholes causing a 'v' shape. They are counter-shaded dark grey and black on top and white on the bottom. The dorsal fin is tall and curved and the flippers are slender and pointed. (1) Minke whales can be between 8 and 10 meters in length (26.2 ft to 32.8 ft) and weigh up to 9,200 kg (20,000 pounds). (4)

Minke whales mostly eat krill, although some eat capelin, cod, herring, pollock, and other fish, depending on their habitat. Sea birds feed opportunistically next to them. (2) They feed in the summer and breed in the winter. In turn, minkes are predated by killer whales. Minke whales can live up to 50 years. (1)

Minke whales reach sexual mature at age six or seven years of age. (4) They breed in the summer, gestate for 10 or 11 months and nurse for four to six months. They calve every two or more years. (1) Calves are darker in color than adult minke whales. Males tend to reside in the polar regions during the summer. Females migrate farther but are generally found in coastal waters. (2)

Minke vocalization is a low frequency grunts and high frequency pings. (4) They are fairly vocal. These vocalizations vary by species and distribution. (2) According to Dr. Costa of UCSC, "if it sounds like Star Wars, it must be minke whales." (5) You can here sounds of the minke whale here.

North Atlantic minkes emit thumps at 100 to 200 Hz for 50 to 70 ms and grunts between 80 and 140 Hz for 165 to 320 ms. (6) North Pacific minkes produce a mysterious sound that has been dubbed 'boing'. It had been observed for years but no one knew where the noise was coming from. I wrote about it and other mysterious sounds back in December 2010 in a post called Echoes from the Deep.

Minkes spend very little time at the surface so they can appear elusive but they are very curious and known to follow boats. (1) They can dive for up to 15 minutes but usually stay down for 6 to 12 minutes. (2) The blowhole and the dorsal fin surface and the same time, which is a useful tool for identification. (4) They sometimes surface so quickly that they create a spray that's often described as a rooster tail. (2) They can be seen in pairs or small groups (4 to 6). They tend to aggregate in larger groups on the poles. They also segregate by age and sex. (1)

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During the heyday of commercial whaling, minke whales were considered too small and fast to hunt. Plus their carcasses sank. But they were hunted when they entered into bays and inlets. (4) When large whale populations were decimated from the commercial hunting, whalers looked toward the minke whale. At least 100,000 have been killed in the southern hemisphere since the 1930s. (2)

They are considered a stable species overall. (2) However, Since the 1960s, minke whales had been hunted by Japan, Russia and Norway. Russia claims to have since stopped and Japan continues. They are hunting from the smallest stock, which means the Japan-stock will not rebound as quickly as they would if their numbers were higher. They are also considered threatened. (2) They are the whales that activists are trying to save from Japanese whalers on Whale Wars. They are protected under the Marine Mammal Protection At of 1972.

I am sure some of you have heard about the shark cafe located roughly half-way between Hawaii and Baja. This cafe, a 400 mile-wide area (2), is a hot spot for solitary-like animals (mostly sharks) to go to mate and eat, or so they think. Most Pacific shark species, such as the white sharks, visit from April to July. (3)

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The spot was named by the Monterey Bay Aquarium Research Institute in 2002, who at the time was studying shark movement via TOPP (Tagging of Pacific Predators — more on that later). Barbara Block's lab from Stanford University provided more satellite tagging data and information. (3)

According to Pete Thomas, who wrote The Great White Way for the Los Angeles Times, it remains a mystery as to why they go there and what they do there. (1) Some refer to it as the equivalent of the desert, with no food, little plankton, or reason for visiting. (2) It would seem that the sharks meet there to migrate but juveniles have also been known to the cafe so it may also be a nursery. (1)

When sharks do go to the cafes, they move at a pace of about one meter per second, diving to 3,000 feet or more. It takes about 25 days for them to arrive. Once at the cafe, their diving behavior has been described as "yo-yo diving", where they dive 700 to 2,00 feet then surface at 16 minute intervals for up to 18 hours. (2) Scientists don't know why they do this either. They are looking for a connection between the presence of tuna and the shark's behavior. (2)

For now, Stanford professor and TOPP Project Leader Salvador Jorgensen says, "It's a place where you might go to get a bite to eat. Or you might go there to meet a person of the opposite sex." (1) 

Be sure to check out the documentary by Sean Aronson called the White Shark Cafe. It's an interesting documentary about following white sharks from San Francisco to the cafe and beyond. It includes some interesting interviews with the famous Dr. John McCosker (who is currently at the California Academy of Sciences) and Salvador Jorgensen.

No, not that Twilight.

I, of course, am referring to the ocean's mesopelagic zone, also known as the disphotic zone. In Greek, disphoric means 'poorly lit'.

Twilight appears a dark blue to black with just enough light to penetrate during the day but not enough for plants to live/photosynthesize in. 

This zone generally spans from 200 m to 1,000 m (660 ft - 3,300 ft) below the ocean. (5) After that are the Bathypelagic zone (the "midnight" zone), the Abyssopelagic zone (the "abyss"), and down to the Hadalpelagic Zone (the "trenches"). (1)

The water is cold. Temperatures ranges from 4 to 20 degrees Celsius (39 to 68 degrees Fahrenheit). (3) The amount of available light, as expected, decreases with depth but the pressure increases. (Remember pressure = force x area; the further down, the more force.) (2) The pressure can be 1,470 psi. Because of this, life here is not very abundant. 

But animals do live and/or migrate through the mesopelagic zone. These include lantern fish, hatchet fish, viper fish, squid, coelacanths (lungfish!), ctenophores, dinoflagellates, dragonfish, fangtooth, gulper eel, hatchet fish, mid-water jelly fish, lantern fish, snipe eels, some octopuses, plankton, polychaetes, radiolarians, siphonophore, rattalk fish, and many worms (including tubeworms). (3)

Here are a few mesopelagic dwellers:

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As you can see, the animals that live in the disphotic zone must be adapted to life in cold, high pressure darkness. Many have large eyes to see in the dark. Most are small, dark and thin (for camouflage), and many have large teeth and jaws.

The mesopelagic's denizens are filter feeders, grazers, and predators. They feed on plant matter and algae that fall into the mesopelagic zone from the epipelagic zone (aka euphotic zone: the well-lit zone). Some animals that live in this zone migrate to the surface to feed. (6) Fish that migrate possess a swim bladder and well developed muscles for such migratory feeding. (7) The ones with large jaws and teeth are adapted to pursue prey even larger than themselves!

Some of the animals in the disphotic zone are bioluminescent, meaning they produce/emit their own light. The animals have photophores. Some are specialized organs produced in the animal. In others, it is symbiotic bacteria. They can be turned off to become invisible in the dark. (7)

Check out the lobate ctenophore below:

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When sea floor mapping began in the 1920s around the time of World War I (9), the sonar operators originally thought that the sea floor wasfound  at 300 meters. That is because the millions of organisms that came up to that level at night to feed were creating a layer that the sonar was picking up as a sea floor. (7) The layer was deeper when the moon was out. This change in depth has been dubbed the deep scattering layer. (8)

Many more animals pass through this layer than I have listed here. It's a pretty cosmopolitan layer that temporarily sees whales, larger sharks, giant squid, and many more interesting creatures of the sea.

Next time you find yourself traversing through the mesopelagic zone take some time to appreciate the scenery! 

I do not eat fish. But if I did, I would consider using the Food and Water Watch's Smart Seafood Guide's new 2011 list, which includes a list of which non-native species that every one should be eating. Yum. 

Invasive species are brought in intentionally (imported or smuggled) or accidentally (through ship ballast water). Many species found in the United States were introduced during the colonization and subsequent conquest of the entire country (Eucalyptus in California for example). 

They threaten native ecosystems and their agricultural, recreational, and commercial viability because invasive species have no natural predators (checks and balance). This causes an unbalanced food web where the invading species predates the current populations or usurps the current population's habitat and food sources. Either way causes a decline of the natural populations and damages the ecosystem. 

According to The Nature Conservancy, "the estimated damage from invasive species worldwide totals more than $1.4 trillion – five percent of the global economy." (3) The National Biological Information Infrastructure estimates $138 billion per year. (4)

Last June I wrote an article about lionfish invading Florida's coasts. Back then people were offering the solution of consumption to rid them of their waters. It seems that the idea has caught on and environmental groups are taking note of this as a viable solution to stave off the tide of invasion.

So far there are nine invasive species suggested by Food and Water Watch. They include:

Asian carp Photo Source Includes several species — bighead, black and silver. Native to Asia, they were brought in 1970s to control algal blooms. They have spread through Great Lakes and the Southeast and consume two to three time their own body weight in phytoplankton and zooplankton per day.

Asian shore crab Photo Source Native to Russia and Japan, they introduces vis ship travel and are now found from Maine to North Carolina. Opportunistic, they will eat anything they come across, leaving little for the native blue crab, rock crab and lobster.  

Asian swamp eel Photo Source Native to Asia, they have invaded Hawai'i, Georgia, Florida and possible New Jersey. Theories of introduction include aquarium escape or fish farm escape in the Southeast or as fish food by Hawai'ian immigrants. As predators, they feed on a number of animals and can live weeks with out food.

Chinese mitten crab Photo Source Native to Southeast Asia, they are thought to have been introduced to California in the 1999s through ship travel. They may also be in New Jersey. In addition to being invasive they are also a nuisance as they clog water pumps and burrow in soil, furthering erosion and levee weakening. They eat endangered plants in California's delta as well as rice crops.

European green crab Photo Source Native to Europe, they were introduced in the 1800s via ship travel. They have since established themselves California up along the coast to British Colombia. They are predators, feeding on a number of crustaceans as well as algae. 

Lionfish Photo Source Native to the western Pacific, thy have become established in early 2000s in the Eastern U.S. Theories o release include aquarium escape or release. They eat fish and invertebrates voraciously and they breed year round. The spines are venomous. Read more here. Here are some lionfish recipes for the adventurous. 

Mozambique and blue tilapia Photo Source Native to southern coastal Africa (Mozambique) and the Middle East and Northern Africa (blue), these two species were introduced when they escaped fish farms. They have established themselves in warm states such as Hawai'i and Florida. They can live in waters with ranging salinity from from to salt water, competing with all native species for habitat and food. 

Rusty crawfish Photo Source Native to Kentucky, Ohio and Indiana, it has since found its way from Maine to Mexico. Because it is a popular bait fish it is believe that it was introduced via recreational fishing. The are opportunistic, greatly reducing diversity in any habitat they reside in. The females also lay 500 eggs at a time.

Walking catfish Photo Source Native to Southeastern Asia, the walking catfish was introduced in southern Florida in the 1960s as a result of the aquarium trade. Because it can survive out of water for periods of time, it allows the walking catfish to expand its territory during times of flooding, even rainy days. 

The full guide to eating invasive species can be found here. 

Others that should be on the list include the European green crab, Ruffle, round goby, sea lampry and zebra mussels. Of course there's a number of invasive species out there (tunicates are increasingly a problem).

And there are many organizations dedicated to discovering them, tracking them, and assessing  their impacts. Columbia University created the Introduced Species Summary Project. There is also the Aquatic Nuisance Species Task Force, The Invasive Species Specialist Group,  and the Global Invasive Species Team. Invasive.org allows you to look for invasive species by state.

Interestingly, most of the introduced species have been traced to ship travel. Marine scientists are investigating ways to reduce species transfer through ballast water as well as other ways to deal with invasive species.

The Food and Water Watch's Smart Seafood Guide is a nice companion piece to The Monterey Bay Aquarium's Seafood Watch. Seafood Watch focuses on the sustainability of the oceans, which includes avoiding unsustainable catch and farming practices. The Smart Seafood Guide considers human health implications such as contaminants and economic, social and cultural implications.