Featured Research

from universities, journals, and other organizations

Seabed Silt In Indian Ocean Consists Of Remains Of Summer Plankton

Date:
April 16, 1999
Source:
Netherlands Organization For Scientific Research
Summary:
Almost 90% of the silt on the floor of the Indian Ocean consists of the remains of plankton that bloomed in the course of the summer monsoon. This has been discovered by earth scientists at the NWO's Netherlands Institute for Sea Research (NIOZ). Their study involved the use of automated sediment traps in which flows of marine material were caught while settling to the deep ocean floor. Because the blooming of plankton is greatly dependent on the monsoon climate, the analysis of oceanic sediments provides insight into climatic changes in the past.

Almost 90% of the silt on the floor of the Indian Ocean consists of the remains of plankton that bloomed in the course of the summer monsoon. This has been discovered by earth scientists at the NWO's Netherlands Institute for Sea Research (NIOZ). Their study involved the use of automated sediment traps in which flows of marine material were caught while settling to the deep ocean floor. Because the blooming of plankton is greatly dependent on the monsoon climate, the analysis of oceanic sediments provides insight into climatic changes in the past.

Only the toughest parts of the plankton are preserved, for example flocs of resistent organic material and the tiny skeletons of the organisms. Most of the other material is recycled near the surface of the sea where it is formed or broken down during settling The researchers were surprised to find that 95% of the plankton's silicon skeleton dissolves just above the deep sea bed soon after arrival. Most of the organic carbon originating from dead plankton flocs is processed biologically in this layer. Only in areas with a low oxygen concentration closer to the shore, the organic carbon eventually ends up buried in the sea bed.

The summer blooming of plankton in the Indian Ocean turns out to be so enormous that despite the fact that a great deal of material is broken down at sea-bed level, the silt consists almost entirely of the remains of this living material. However, the lime which was found on the deep sea bed closer to the land turned out to be composed primarily of shell fragments and only partly of the remains of plankton skeletons. The shell fragments are produced in coastal waters and are washed into the deep ocean at the end of the summer monsoon. This is apparent from the large quantities of shell fragments which the researchers discovered in their deep-sea sediment traps in the late summer.

The cause of the summer plankton explosion is the south-western monsoon along the edge of the Indian Ocean. This pumps up the nutrients required for the plankton to bloom, including nitrate and phosphate, from deeper water levels into the well lit surface ocean. Conditions for growth are therefore at their best during the summer in the top 150 metre layer of the ocean.

This understanding of the most important sources of the various kinds of silt on the floor of the Indian Ocean provides earth scientists with a natural climatological "archive" covering the past several thousand years.


Story Source:

The above story is based on materials provided by Netherlands Organization For Scientific Research. Note: Materials may be edited for content and length.


Cite This Page:

Netherlands Organization For Scientific Research. "Seabed Silt In Indian Ocean Consists Of Remains Of Summer Plankton." ScienceDaily. ScienceDaily, 16 April 1999. <www.sciencedaily.com/releases/1999/04/990416082351.htm>.
Netherlands Organization For Scientific Research. (1999, April 16). Seabed Silt In Indian Ocean Consists Of Remains Of Summer Plankton. ScienceDaily. Retrieved July 30, 2014 from www.sciencedaily.com/releases/1999/04/990416082351.htm
Netherlands Organization For Scientific Research. "Seabed Silt In Indian Ocean Consists Of Remains Of Summer Plankton." ScienceDaily. www.sciencedaily.com/releases/1999/04/990416082351.htm (accessed July 30, 2014).

Share This




More Plants & Animals News

Wednesday, July 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Thousands Flocking to German Crop Circle

Raw: Thousands Flocking to German Crop Circle

AP (July 30, 2014) Thousands of people are trekking to a Bavarian farmer's field to check out a mysterious set of crop circles. (July 30) Video provided by AP
Powered by NewsLook.com
Concern Grows Over Worsening Ebola Crisis

Concern Grows Over Worsening Ebola Crisis

AFP (July 30, 2014) Pan-African airline ASKY has suspended all flights to and from the capitals of Liberia and Sierra Leone amid the worsening Ebola health crisis, which has so far caused 672 deaths in Guinea, Liberia and Sierra Leone. Duration: 00:43 Video provided by AFP
Powered by NewsLook.com
At Least 20 Chikungunya Cases in New Jersey

At Least 20 Chikungunya Cases in New Jersey

AP (July 30, 2014) At least 20 New Jersey residents have tested positive for chikungunya, a mosquito-borne virus that has spread through the Caribbean. (July 30) Video provided by AP
Powered by NewsLook.com
Raw: Otters Enjoy Water Slides at Japan Zoo

Raw: Otters Enjoy Water Slides at Japan Zoo

AP (July 30, 2014) River otters were hitting the water slides to beat the summer heatwave on Wednesday at Ichikawa City's Zoological and Botanical Garden. (July 30) Video provided by AP
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