Tuesday, November 10, 2009

Goodbye Great White

[Originally posted to MBA Student Oceanography Club (SOC)]

White Shark

The aquarium recently released the captive white shark that had been on display, but don't shed too many tears for her. As sad as it is to see her go, just think that now she can roam the entire Pacific, perhaps taking a much needed vacation to Hawaii before coming back to visit our local beaches again. At least that is what researchers have found that many other great whites have done:




  • http://www.washingtonpost.com/wp-dyn/content/article/2009/11/03/AR200911...

  • Researchers at the Monterey Bay Aquarium, Stanford University, and other organizations have been tracking these sharks for a decade now, and have found that great whites travel widely, but regularly return to our coast. Even so, the recently released shark will still regularly call to let us know how she's doing. For example, a couple of weeks ago she let us know that she was visiting the Monterey Canyon:




  • http://montereybayaquarium.typepad.com/sea_notes/2009/11/white-peacock.html

  • If you want to follow the latest news on the tagged great whites (or tuna, turtles, marine mammals or other pelagic predators for that matter), check out the Tagging of Pacific Predators web site:




  • http://www.topp.org/species/white_shark

  • Click on the "Near real-time tracking" button on the map to see where different animals are located. Our girl is listed under "Juvenile White Shark" with the ptt # 95118 and TOPP ID # 3309004. She is currently hanging out with the surfers near Santa Barbara.

    Saturday, October 17, 2009

    Salps in the bay


    [Originally posted to MBA Student Oceanography Club (SOC)]
    During our kayak trip, we saw some pretty cool organisms. Among the more unique were salps, the gelatinous creatures that were swimming everywhere. Salps are tunicates, marine chordates identified by their rigid tunic (also known as a test). Most tunicates, commonly known as sea squirts, are sessile, meaning they live permanently in one place firmly attached to the bottom. The 24 species of salps, however, have adopted a free-swimming, pelagic lifestyle. All are transparent, tubular, gelatinous animals that swim via jet propulsion as they pass water through their bodies.

    Salps feed continuously on plankton and detritus as they swim. A mucus net captures particles suspended in the water that passes through the salp’s body. The net is constantly renewed, and cilia move the mucus like a conveyor belt into the gut. They are very efficient feeders, and some of the fastest growing of all multicellular animals; one species can increase its body size by as much as 20% per hour! Salps also reproduce rapidly, with generation times of several days. Because of their rapid reproduction and incredible growth rates, when phytoplankton is abundant, salps can form massive blooms. They can swarm by the millions or even billions until they filter out most of the plankton in the surrounding water, at which point the populations crash.

    We likely witnessed such a bloom during our kayak trip. The species that we saw in the bay was probably Cyclosalpa affinis. Cyclosalpa can consume approximately half of their body mass in 24 hours, increase in body size by about 25% a day, and reproduce quickly, explaining the huge number that were present in the bay for several days. Like other salps, Cyclosalpa have a complex life cycle that alternates between solitary, asexually reproducing generations, and aggregate, sexually reproducing generations. The solitary phase, called an oozoid (shown in photo 1), buds chains of aggregate salps, called blastozooids (the arrow in photo 2 shows the budding chain coming from an oozoid). In some species, this chain can be up to 15 feet long. In Cyclosalpa, however, the aggregate salps form rings of individuals (shown in photo 3). The aggregate individuals remain attached while swimming and feeding, growing and reproducing as a unit. The aggregate salps are sequential hermaphrodites, starting life as females, and becoming males when they grow larger. Chains of small female salps will therefore mate with chains of larger male salps, and embryos are gestated within the female’s body wall. The embryos develop into solitary salps and are released, beginning the cycle anew.

    Salps are an important part of the pelagic ecosystem. They are food for many predators, including jellyfish, fish, sea turtles and birds, and host a number of other organisms, including parasitic crustaceans and fish (the arrow in photo 3 shows a parasitic amphipod residing in a blastozooid). The fecal pellets formed from their prodigious feeding are also a major source of food for mid-water and deep-sea creatures.

    Salp Oozoid Budding Oozoid Blastozoid with parasitic amphipod

    Tuesday, August 18, 2009

    Girl Gets Too Close to Sea Lion

    [Originally posted to the Marine Photobank]

    A beach-goer approaches a sea lion.


    Description:
    A beach-goer approaches a resting sea lion much to closely in an attempt to pose for a photograph.

    Exposure Date:
    8/8/2009

    Gallery:
    Photo Contest 2010, Ocean Tourism/Recreation

    City/Region:
    Carmel

    State/Province:
    California

    Country:
    United States


    Download:
    http://www.marinephotobank.org/secure/gallery-photo.php?photo_id=7372

    Copyright Statement :
    Image may be used for non-commercial and media purposes only. Credit should state, "Gerick Bergsma 2010/Marine Photobank."

    Additional Comments:
    marine mammal protection act, human disturbance, sealion

    Sea Otters Grooming

    [Originally posted to the Marine Photobank]

    Sea otters grooming themselves in Monterey Bay.


    Description:
    Southern sea otters groom themselves near the mouth of the Elkhorn Slough Estuary in Moss Landing, California.

    Exposure Date:
    7/4/2009

    Gallery:
    Closed: Photo Contest 2009: Ecosystem Decline/ Species of Concern, Marine Species of Concern

    City/Region:
    Moss Landing

    State/Province:
    California

    Country:
    United States


    Download:
    http://www.marinephotobank.org/secure/gallery-photo.php?photo_id=6719

    Copyright Statement :
    Image may be used for non-commercial and media purposes only. Credit should state, "Gerick Bergsma 2009/Marine Photobank."

    Tuesday, August 4, 2009

    San Francisco Bay Marina and Golf

    [Originally posted to the Marine Photobank]

    A Marina and Golf Course sit along the San Francisco Bay.


    Description:
    The Coyote Point Marina, the Poplar Creek Golf Course and a power substation are just some of the uses for the heavily developed shore along the San Francisco Bay near San Mateo, California.

    Exposure Date:
    8/2/2009

    Gallery:
    Coastal Development, Ocean Tourism/Recreation

    City/Region:
    San Mateo

    State/Province:
    CA

    Country:
    United States


    Download:
    http://www.marinephotobank.org/secure/gallery-photo.php?photo_id=6939

    Copyright Statement :
    Image may be used for non-commercial and media purposes only. Credit should state, "Gerick Bergsma 2009/Marine Photobank."

    Friday, July 31, 2009

    Spinner Dolphin

    [Originally posted to the Moorea Coral Reef LTER (MCR LTER) Marine Life Encyclopedia]

    Spinner Dolphin
    (Stenella longirostris)

    Spinner Dolphin  - Stenella longirostris
    Photo by Gerick Bergsma

    Spinner dolphins commonly form large groups, often with other species, including other dolphins and even tuna.  Unfortunately, this has made them a common casualty of the tuna fishery.

    Distribution
    Found throughout the world's tropical oceans.

    Habitat
    Found on reef slopes and out in the open ocean.

    Diet
    Spinner dolphins feed on fish and squid.

    Quick Fact
    Spinner dolphins are known for their acrobatics, and frequently jump out of the water and spin through the air. They, like other dolphins, use echolocation to navigate and track prey, and often feed at night.

    Learn More
    - MarineBio.org

    - Moorea Biocode Database

    Downtown Seattle Skyline

    [Originally posted to the Marine Photobank]

    Downtown Seattle, Washington, and its waterfront on Elliot Bay in the Puget Sound, with Mt. Rainier visible in the background.


    Description:
    Seattle is a large urban center and major port along the US West Coast.

    Exposure Date:
    11/23/2007

    Gallery:
    Coastal Development

    City/Region:
    Seattle

    State/Province:
    Washington

    Country:
    United States


    Download:
    http://www.marinephotobank.org/secure/gallery-photo.php?photo_id=6923

    Copyright Statement :
    Image may be used for non-commercial and media purposes only. Credit should state, "Gerick Bergsma 2008/Marine Photobank."

    Humpback Whale

    [Originally posted to the Moorea Coral Reef LTER (MCR LTER) Marine Life Encyclopedia]

    Humpback Whale
    (Megaptera novaeangliae)

    Humpback Whale - Megaptera novaeangliae
    Photo by Hannah Stewart. Text by Gerick Bergsma.

    Humpback whales migrate annually between the food-rich waters near the poles and the warm tropical seas where they breed.  Individual whales have been identified as migrating from Antarctica to Costa Rica, the longest migration by any mammal.

    Distribution
    Humpback Whales are found throughout the world's oceans, migrating between polar and tropical seas.

    Habitat
    Found offshore in the open ocean

    Diet
    Eat krill and small fish

    Quick Fact
    Humpback whales are famous for their songs.  The songs, which can last up to 20 minutes and are often repeated for hours on end, are only produced by males during the breeding season and might serve to announce a male's presence to other males or to attract females.  Whales from a given region typically share the same song, but songs differ from region to region.

    Learn More
    - Animal Diversity Web

    - Moorea Biocode Database

    Yellowfin Tuna

    [Originally posted to the Moorea Coral Reef LTER (MCR LTER) Marine Life Encyclopedia]

    Yellowfin Tuna - Aahi re'are'a
    (Thunnus albacares)

    Yellowfin Tuna - Thunnus albacares
    Photo by Gerick Bergsma
    Yellowfin tuna often school with other fish of similar size.  Smaller individuals are often found in large single-species schools or in schools with other species of tuna, while larger individuals are sometimes found schooling with dolphins or porpoises.

    Distribution
    Yellowfin Tuna occur throughout the world's tropical oceans.

    Habitat
    Yellowfin Tuna are found out in the open ocean.

    Diet
    Yellowfin feed on fish, crustaceans and squid.

    Quick Fact
    Yellowfin tuna are fast swimmers, and can reach speeds of 70 kilometers per hour (~45 miles per hour).  They roam widely, and have been known to move over 1,000 km in a year.

    Learn More
    - Florida Museum of Natural History

    - Moorea Biocode Database