BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: Ocean

Seagrasses: Benefitting the Ecosystem

Seagrasses have been known to improve water quality greatly, however it was only recently that scientists discovered other major benefits of the plants that reside in the ocean. The name seagrasses is a misnomer, for they are actually plants that grow in shallow ocean water. Seagrasses are one of the largest stores of carbon in the ocean, and they also remove excess nitrogen and phosphorous from the water.

A few years however, ecologist Joleah Lamb’s colleagues fell ill with amoebic dysentery. This is an intestinal illness that they contracted while conducting research on coral reefs in Indonesia. The illness can be caused by the release of raw sewage into the ocean by a city, which leads to a drastic increase in the populations of shoreline bacteria. The water collected close to the shore had been compared to offshore tidal flats and coral reefs with seagrass beds. The two different sites were very close to one another, yet the water where the seagrass was had a significantly smaller amount of Enterococcus bacteria. The bacteria in areas with seagrass was only 1/3 of that in other areas that did not have the plants. This bacteria is not only dangerous for humans, but is harmful for fish and other species as well.

While at this moment it is uncertain how the seagrasses clean the water, we know that seagrasses trap small particulates and prevent them from flowing on in the ocean. It is believed that the plants would catch the bacteria in the same way, or that the leaves might emit antimicrobial compounds that directly kill the bacteria. Another possibility could be that seagrasses release oxygen made during photosynthesis, and the oxygen is toxic to pathogens. Also, it is noted that seagrass meadows often are located next to coral reefs, so some suggest that they work together to protect one another from bacteria and other possible dangers.

 

Further reading:

http://www.smithsonianmag.com/smart-news/seagrasses-reduce-bacteria-polluted-waters-180962177/

https://www.newscientist.com/article/2121502-seagrass-meadows-help-remove-dangerous-bacteria-from-ocean-water/

https://www.health.ny.gov/diseases/communicable/amebiasis/fact_sheet.htm

Too Hot to Handle?

Climate scientist Axel Timmermann has recently stated that “this summer has seen the highest global mean sea surface temperatures ever recorded since their systematic measuring started. Temperatures even exceed those of the record-breaking 1998 El Niño year.” Timmermann has been studying the global climate system and according to his studies, the “Global Warming Hiatus” came to an end in April 2014.

He says that the North Pacific has been the cause of most of the global ocean warming, whose temperature has risen far above any recorded temperatures, has shifted hurricane tracks, and has changed trade winds. There has even been coral bleaching in the waters surrounding the Hawaiian Islands. Apparently, this began in January 2014 when the sea-surface temperatures suddenly began to rise at an unusual rate. Then in April and May, the warm waters of the western Pacific spread to the eastern Pacific, releasing large amounts of heat into the atmosphere. This heat hadn’t been in the atmosphere for nearly a decade.

Ocean Temperatures

(Sea Surface Temperatures 2003-2011)

Timmermann says that “record-breaking greenhouse gas concentrations and anomalously weak North Pacific summer trade winds, which usually cool the ocean surface, have contributed further to the rise in sea surface temperatures.” These warm temperatures have been spreading all the way to the Gulf of Alaska.

As this 14-year break in the ocean warming comes to an end, more questions come to the surface: What can we do? What other effects will this have on other environments? Will there be another hiatus?

Certainly this is just another piece in the puzzle of the larger global warming issue, and if it isn’t reversible, how can we stop other similar issues?

Seals in the Antarctic

Today, thanks to modern technology and social networking, there are few parts of the world that remain inaccessible. You can learn things about places you have never been just from looking on your computer screen. However, there are still small parts of the world unexplored and untouched by humans. Antarctica is one of those places sheltered from humans by impossible weather and environment conditions.  “In fact, About 98% of Antarctica is covered by ice that averages at least 1 mile (1.6 km) in thickness” and the average temperature of the continent is -49 degrees celsius.

Explorers and scientists have attempted to learn what they can about the frozen continent but time spent there is limited. Even more seemingly impossible to reach is the Antarctic Ocean Floor. It is tough to study the “extreme Antarctic environment, where observations are very rare and ships could not go”.  To fix this gap of knowledge, scientists attached sensors to the heads of elephant seals. These seals are adapted to the freezing conditions so they can survive in the Arctic ocean with a temperature average of .5 degree celsius.

Southern Elephant Seal image taken from WikimediaCommons

 

Thanks to the elephant seals, “scientists better understand how the ocean’s coldest, deepest waters are formed, providing vital clues to understanding its role in the world’s climate”. The seals allowed greater insight to the Antarctic bottom water-

“a layer of water near the ocean floor that has a significant impact on the movement of the world’s oceans”. These areas were previously known of but no real data had been obtained. The seals went to areas of the coast line where “no boat could ever go”.

Studies have shown 50 year long trends in these deep water changes. Scientists hope the new data obtained through the seals will help to further uncover these trends that affect global climate change.

Main Article:

http://www.nbcnews.com/id/50952475/ns/technology_and_science-science/#.US1HFc1RLzc

Additional Articles:

http://www.gma.org/surfing/antarctica/antarctica.html

http://en.wikipedia.org/wiki/Antarctica

Picture Link:

http://commons.wikimedia.org/wiki/File:Southern_Elephant_seal.jpg

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