Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Nurseries in the deep sea

04.09.2003


Exploring a deep-sea ridge off Northern California, scientists at the Monterey Bay Aquarium Research Institute (MBARI) have discovered a unique undersea nursery, where groups of fish and octopus brood their eggs, like chickens on their nests. This is the first time that marine biologists have directly observed any deep-sea fish brooding its eggs. It is also the first time that two different types of mobile deep-sea animals have been observed brooding together in the same area. Although the scientists do not know exactly why the animals prefer this one area, they believe that the nursery represents a new type of biological “hot spot” (an area of intense biological activity).


A blob sculpin (Psychrolutes phrictus) peers over the edge of a boulder at the ROV Tiburon. This fish is guarding its eggs (which you can see in the background) along the Gorda Escarpment, off Northern California. Blob sculpin commonly grow to 60 cm (2 feet) in length. The animals on the rock are brisingid sea stars (with the feathery arms) and sea anemones. Image (c) 2002 MBARI


Three octopus (Graneledone sp.) brood their eggs on a rock outcrop along the Mendocino Escarpment, offshore of Northern California. The octopus are in a typical brooding position, with their heads down and arms curled outward. Their eggs are hidden underneath their bodies, which are about 16 cm (6 inches) across. Also on the rock are a deep-sea crab and several types of sea anemones. This photograph suggests some of the abundance and diversity of marine life found around the undersea nursery areas along the Gorda Escarpment off Northern California. Image (c) 2002 MBARI



MBARI scientist Jeff Drazen presented these observations last week at the Deep Sea Biology Symposium in Coos Bay, Oregon. His research is also featured in the current (August 2003) issue of Biological Bulletin, which shows photographs of the brooding fish and octopus on its cover.

The undersea nursery was discovered and documented using MBARI’s remotely operated vehicle (ROV) Tiburon. Using video tapes from Tiburon dives, Drazen and colleagues found that each summer, blob sculpin (Psychrolutes phrictus) and deep-sea octopus (Graneledone sp.) gather together at the crest of the Gorda Escarpment, off Northern California.


"The sculpin nests look like large splotches of purple strewn across the surfaces of boulders,” says Drazen. “The parent fish is usually resting on the seafloor near or on top of the eggs. When I first saw this in the video, I was surprised because no one had ever documented such behavior in a deep-sea fish before.” Blob sculpin are typically about 60 cm (2 feet) long and shaped like large, flabby tadpoles. Drazen estimates that some sculpin nests may contain up to 100,000 eggs. The nursery area lies near the crest of an undersea rise, almost a mile below the ocean surface.

MBARI geologists first encountered these nursery areas in August 2000. While performing geological surveys with ROV Tiburon, they noticed that octopus and blob sculpin were common near certain cold seeps, where hydrocarbon-rich fluids seep out of the seafloor. When they returned to the region in 2001, they brought along biologists, who realized that the octopus were present in unusually large numbers. On one dive, the ROV also brought up a rock sample which was covered with eggs. It wasn’t until later, when Drazen watched videotapes of these dives, that he realized both the fish and the octopus might be brooding eggs. Intrigued, Drazen organized a third dive in July 2002, to count the animals and their eggs and to make more observations. The high densities of animals measured in certain areas convinced Drazen that these nurseries might qualify as biological hot spots.

Previously discovered biological hot spots in the deep sea, such as hydrothermal vents and the tops of seamounts, have been related to geological or topographic features that cause an increase the availability of food. The nurseries on the Gorda Escarpment may represent a totally different type of hot spot, where physical conditions particularly favor the development of eggs. Drazen is still not sure what aspect of the physical environment makes this spot so popular for brooding animals.

Whatever the key conditions may be, Drazen points out that these areas are critical habitat for the species involved. He and his co-authors are concerned that these undersea nurseries could be endangered by commercial trawling or long-line fishing. Such fishing has expanded into the deep sea as near-shore fish stocks have declined. For this reason, Drazen suggests that reproductive hot spots such as this might qualify as areas to be protected from fishing.

Finding one reproductive hot spot may also help scientists discover other such areas. But as Drazen points out, “Unlike hydrothermal vent and seamount communities, which persist for generations, reproductive hot spots may be seasonal and transitory. This makes such sites especially hard to find. We hope to learn more about why these animals aggregate on the ridge and use this information to narrow our search for other important nurseries in the deep sea.”

Debbie Meyer | MBARI
Further information:
http://www.mbari.org/news/news_releases/2003/nr05-drazen.html

More articles from Life Sciences:

nachricht Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

17.01.2017 | Materials Sciences

Smart homes will “LISTEN” to your voice

17.01.2017 | Architecture and Construction

VideoLinks
B2B-VideoLinks
More VideoLinks >>>