Microbial community structure shifts are associated with temperature, dispersants and nutrients in crude oil-contaminated seawaters

Title	Microbial community structure shifts are associated with temperature, dispersants and nutrients in crude oil-contaminated seawaters
Publication Type	Journal Article
Year of Publication	2016
Authors	Meng L., Liu H., Bao MT, Sun PY
Journal	Marine Pollution Bulletin
Volume	111
Pagination	203-212
Date Published	Oct
ISBN Number	0025-326X
Accession Number	WOS:000384854100032
Keywords	Deepwater Horizon
Abstract	This study tracked structure shifts of bacterial compositions before, during and after invading by crude oil to determine the microbial response and explore how temperature, dispersants and nutrients affect the composition of microbial communities or their activities of biodegradation in artificial marine environment. During petroleum hydrocarbons exposed, the composition and functional dynamics of marine microbial communities were altered, favoring bacteria that could utilize this rich carbon source such as the Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes phyla. Low temperature as a dominant factor decreased bacterial richness and catabolic diversity due to abated enzymes activities in correlation with the process of biodegradation. Dispersants exerted no negative consequences on microbial composition, however, bacterial composition by the Chloroflexi, TM6, OP8, Cyanobacteria and Gemmatimonadetes phyla increased. It seemed that more frequent fertilizer application could be equally safe to bacteria and increased significantly the abundance of bacterial strains but Actinobacteria phyla decreased. (C) 2016 Elsevier Ltd. All rights reserved.
DOI	10.1016/j.marpolbul.2016.07.010

Why the Oceans Matter

From National Geographic

These vast bodies of water surrounding the continents are critical to humankind. But overfishing and global warming threaten to leave this vital habitat barren.

The ocean is a continuous body of saltwater that covers more than 70 percent of the Earth's surface. Ocean currents govern the world's weather and churn a kaleidoscope of life. Humans depend on these teeming waters for comfort and survival, but global warming and overfishing threaten to leave the ocean agitated and empty.

Geographers divide the ocean into four major sections: the Pacific, Atlantic, Indian, and Arctic. Smaller ocean regions are called seas, gulfs, and bays, such as the Mediterranean Sea, Gulf of Mexico, and the Bay of Bengal. Stand-alone bodies of saltwater like the Caspian Sea and the Great Salt Lake are distinct from the world's oceans.

The oceans hold about 320 million cubic miles (1.35 billion cubic kilometers) of water, which is roughly 97 percent of Earth's water supply. The water is about 3.5 percent salt and contains traces of all chemical elements found on Earth. The oceans absorb the sun's heat, transferring it to the atmosphere and distributing it around the world via the ever-moving ocean currents. This drives global weather patterns and acts as a heater in the winter and an air conditioner in the summer.

Life began in the ocean, and the ocean remains home to the majority of Earth's plants and animals—from tiny single-celled organisms to the blue whale, the planet's largest living animal.

Most of the ocean's plant life consists of microscopic algae called phytoplankton that float at the surface and through photosynthesis produce about half of the oxygen that humans and all other terrestrial creatures breathe. Seaweed and kelp are big algae easily visible to the naked eye. Marine plants with roots, like seagrasses, can only survive as deep as the sun’s rays can support photosynthesis—about 650 feet (200 meters). Nearly half of the ocean is more than 9,800 feet (3,000 meters) deep.

The deepest reaches of the ocean are largely devoid of life, but biological hotspots appear around places like hydrothermal vents. These chimney-like structures spew gases and mineral-rich water from beneath the Earth's crust. Tube worms, clams, and mussels gather around the vents to feed on heat-loving bacteria. Bizarre fish with sensitive eyes, translucent fangs, and bioluminescent lures lurk about in nearby waters.

Other fish, octopuses, squid, eels, dolphins, and whales ply the open waters while crabs, lobsters, starfish, oysters, and snails crawl and scoot along the ocean bottom. Creatures like jellyfish lack their own way to get around and are mostly left to the whim of the wind and currents. Mammals like otters, walruses, and even polar bears also depend on the ocean for their survival and dip in and out as their biology requires.

Colonies of polyps form coral reefs as they die. The reefs are mostly found in shallow tropical waters and are home to a brilliant mosaic of polyps, plants, and fish. Coral reefs are also visible victims of human activity. Global warming, siltation, pollution, and other phenomena are stressing the corals to death, and overzealous fishers net more food than the reefs can restore.