Featured Research

from universities, journals, and other organizations

Sharks from deep waters of Cantabrian Sea are opportunist hunters

Date:
April 9, 2010
Source:
FECYT - Spanish Foundation for Science and Technology
Summary:
A team of Spanish researchers has studied the diet of three species of sharks living in the deep waters in the area of El Cachucho, the first Protected Marine Area in Spain, which is located in the Cantabrian Sea off the coast of Asturias. These animals feed on the resources available in their environment, according to changes taking place in the ocean depths.

New research shows that sharks from the deep waters of the Cantabrian Sea are opportunist hunters.
Credit: OCEANA

A team of Spanish researchers has studied the diet of three species of sharks living in the deep waters in the area of El Cachucho, the first Protected Marine Area in Spain, which is located in the Cantabrian Sea off the coast of Asturias. These animals feed on the resources available in their environment, according to changes taking place in the ocean depths.

"All the sections of the food chain are inter-related in these deep-sea ecosystems, and a small change in any one of the links in this chain can cause great changes in the rest," says Izaskun Preciado, lead author of the study and a researcher at the Oceanographic Centre in Santander, which is run by the Spanish Institute of Oceanography (IEO).

In order to gain a detailed understanding of the species that inhabit El Cachucho (Spain's first Protected Marine Area located off the coast of Llanes in Asturias), the scientists studied three species of shark that live at depths of between 400 and 1,000 metres, the blackmouth catshark (Galeus melastomus), the velvet belly lantern shark (Etmopterus spinax), and the birdbeak dogshark (Deania calcea).

The researcher says the results of the study, which has been published in the Journal of Fish Biology, showed that "the sharks' diet is opportunist, because they feed off whatever resources are available, in this case small euphausiid crustaceans, benthopelagic prawns and fish."

Two different habitats

The samples gathered between October 2003 and April 2004 made it possible to define two different habitats -- the top of the bank, at a depth of 454 to 642 metres and covered with a fine layer of sediments with a low percentage of organic material, and the interior of the inner basin, which separates the bank from the continental shelf, at a depth of between 810 and 1,048 metres.

The study shows that the top of the bank (400-500 metres) is inhabited by two of the three shark species studied (the blackmouth catshark and the velvet belly lantern shark). "However, the velvet belly lantern shark is substituted in the deeper parts of the basin by the birdbeak dogshark," explains Preciado.

In the deepest waters, the scientists sampled down to a depth of 1,100 metres and found that the blackmouth catshark and the birdbeak dogshark coexist there without any trophic competition between them, "since each one has specialised to eat a particular kind of food," says the oceanographer.

Predicting changes in the trophic chain

The team stresses the importance of these studies in monitoring species in the El Cachucho area. "It is likely that the establishment of the Protected Marine Area will cause changes in the abundance of certain species of fish, above all commercial ones. For this reason, understanding the trophic network of these ecosystems will help us to predict future changes in the abundance of species," explains Preciado.

The researcher warns: "A significant increase in a predator species could lead to a drastic decline in its prey, and so understanding the dynamics of the trophic networks will help us to predict changes in each of the sections of the ecosystem."

The presence of larger blackmouth catsharks in shallow waters, for example, is a good indicator of higher levels of zooplankton production in these areas.

El Cachucho is an undersea mountain located in the Cantabrian Sea, off the coast of Asturias. At around 4,500 metres in height (measured from its base on the deep-water plain of the Bay of Biscay), it has great faunal and biological wealth. It is the first exclusively marine reserve in Spain. To date, only parks such as Doρana, Cabrera and the Atlantic Islands of Galicia had extended their protection to include part of the maritime environment.


Story Source:

The above story is based on materials provided by FECYT - Spanish Foundation for Science and Technology. Note: Materials may be edited for content and length.


Journal Reference:

  1. Preciado, I.; Cartes, J.E.; Serrano, A.; Velasco, F.; Olaso, I.; Sαnchez, F.; Frutos, I. Resource utilization by deep-sea sharks at the Le Danois Bank, Cantabrian Sea, north-east Atlantic Ocean. Journal of Fish Biology, 2009; 75 (6): 1331 DOI: 10.1111/j.1095-8649.2009.02367.x

Cite This Page:

FECYT - Spanish Foundation for Science and Technology. "Sharks from deep waters of Cantabrian Sea are opportunist hunters." ScienceDaily. ScienceDaily, 9 April 2010. <www.sciencedaily.com/releases/2010/03/100317101338.htm>.
FECYT - Spanish Foundation for Science and Technology. (2010, April 9). Sharks from deep waters of Cantabrian Sea are opportunist hunters. ScienceDaily. Retrieved April 18, 2014 from www.sciencedaily.com/releases/2010/03/100317101338.htm
FECYT - Spanish Foundation for Science and Technology. "Sharks from deep waters of Cantabrian Sea are opportunist hunters." ScienceDaily. www.sciencedaily.com/releases/2010/03/100317101338.htm (accessed April 18, 2014).

Share This



More Plants & Animals News

Friday, April 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

The Great British Farmland Boom

The Great British Farmland Boom

Reuters - Business Video Online (Apr. 17, 2014) — Britain's troubled Co-operative Group is preparing to cash in on nearly 18,000 acres of farmland in one of the biggest UK land sales in decades. As Ivor Bennett reports, the market timing couldn't be better, with farmland prices soaring over 270 percent in the last 10 years. Video provided by Reuters
Powered by NewsLook.com
Flamingo Frenzy Ahead of Zoo Construction

Flamingo Frenzy Ahead of Zoo Construction

AP (Apr. 17, 2014) — With plenty of honking, flapping, and fluttering, more than three dozen Caribbean flamingos at Zoo Miami were rounded up today as the iconic exhibit was closed for renovations. (April 17) Video provided by AP
Powered by NewsLook.com
Change of Diet Helps Crocodile Business

Change of Diet Helps Crocodile Business

Reuters - Business Video Online (Apr. 16, 2014) — Crocodile farming has been a challenge in Zimbabwe in recent years do the economic collapse and the financial crisis. But as Ciara Sutton reports one of Europe's biggest suppliers of skins to the luxury market has come up with an unusual survival strategy - vegetarian food. Video provided by Reuters
Powered by NewsLook.com
Could Even Casual Marijuana Use Alter Your Brain?

Could Even Casual Marijuana Use Alter Your Brain?

Newsy (Apr. 16, 2014) — A new study conducted by researchers at Northwestern and Harvard suggests even casual marijuana use can alter your brain. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins