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Ocean Research

2018:  FEB

December 2017 Issue

Corals Seem to Like
The Taste of Microplastics

A new Duke University study of plastic ingestion by corals suggests that visual cues, such as a resemblance to prey, don’t factor into the appeal of microplastics as food because corals have no eyes. Instead, corals go by taste.

Corals in the experiments ate all types of plastics but preferred unfouled microplastics by a threefold difference over microplastics covered in bacteria. This suggests the plastic itself contains something that makes it tasty.

When plastic comes from the factory, it has hundreds of chemical additives. Any one of these chemicals or a combination of them could be acting as a stimulant that makes plastic appealing to corals. Further research will be needed to identify the specific additives that make the plastic so tasty to corals and determine if the same chemicals act as feeding stimulants to other marine species.

Because plastic is largely indigestible, it can lead to intestinal blockages, create a false sense of fullness or reduce energy reserves in animals that consume it. It can also leach hundreds of chemical compounds into their bodies and the surrounding environment. The biological effects of most of these compounds are still unknown, but some, such as phthalates, are confirmed environmental estrogens and androgens—hormones that affect sex determination.

Wave Glider Helps Assess
Great Barrier Reef Health

The Australian Institute of Marine Science (AIMS), in partnership with Boeing, has demonstrated how a high‐tech autonomous ocean vehicle can improve monitoring of the Great Barrier Reef and coastal waters. A seven‐day trial saw the vehicle cover 200 nautical miles of the central Great Barrier Reef in what is the first major milestone of a five‐year joint research agreement.

The Wave Glider vehicle, developed by Boeing subsidiary Liquid Robotics, was deployed to help assess the health of the coral reefs and ecosystems. Powered by waves and sun, the vehicle provided continuous, real‐time environmental ocean data using onboard sensors and software. The technology allowed scientists to measure atmosphere and water over long periods of time.

Shrimp Parasite Study Might Have
Implications for Human Health

Tiny shrimp infected by a microscopic parasite are growing in abundance in nutrient-fueled salt marshes and may well portend future threats to humankind.

The study, co-authored by Dr. Richard Heard of the University of Southern Mississippi’s Gulf Coast Research Laboratory, builds on a long-term experiment in which researchers have been adding nitrogen to a New England salt marsh each year since 2004 to investigate how these key coastal ecosystems respond to nutrient-rich runoff from fertilized fields, wastewater treatment plants and other human sources.

To reproduce, the parasite needs to get into the gut of a bird. Turning the amphipod bright orange makes it become attractive to birds. This research could shed light on whether what happens at the bottom of the food web ripples upward.

The study involved counting the number of infected and parasite-free amphipods in fertilized and unfertilized plots each summer from 2009 to 2014.

They discovered that the prevalence of the parasite increased to 13 times higher in nutrient-enriched marshes, while the biomass density of infected amphipods was on average 11 times higher.

This work may provide insights between human activities and disease emergence. Nutrient pollution could enhance the populations of parasites that affect humans, thereby promoting disease.

Ceres Has Possible
Remnants of Ancient Ocean

Minerals containing water are widespread on Ceres, suggesting the dwarf planet may have had a global ocean in the past. In one study, NASA’s Dawn mission team found Ceres’s crust is a mixture of ice, salts and hydrated materials that were subjected to past and possibly recent geologic activity, and this crust represents most of that ancient ocean. The second study builds off the first and suggests there is a softer, easily deformable layer beneath Ceres’s rigid surface crust, which could be the signature of residual liquid left over from the ocean.

The team thinks most of Ceres’s ancient ocean is now frozen and bound up in the crust, remaining in the form of ice, clathrate hydrates and salts. But if there is residual liquid underneath, that ocean is not yet entirely frozen.

$1.2 Million to Develop
Hadal Water Column Profiler

The deepest zone in the ocean, the hadal zone, is deeper than 3.75 mi. (6,000 m). Very little is known about the circulation, mixing, chemical properties and biological communities in the water of these deep-ocean trenches.

This dearth of knowledge stems from a lack of suitable instrumentation with which to make observations.

With a $1.2 million award from the W.M. Keck Foundation, a team from the University of Hawaii at Manoa, along with industry partners, is on track to build a hadal water column profiler (HWCP). It will, for the first time: enable high-quality physical, chemical and biological sampling of the water column from the sea surface to the seafloor at 11 km (36,000 ft.) depth; withstand hundreds of cycles up and down in the water column; and provide observations needed to illuminate important problems, such as how the deep-ocean trenches are ventilated.

Research possible thanks to HWCP will create new understanding of the deep ocean’s impact on the climate and biological communities. Seismic Research System

For Canary Archipelago
The underwater volcano Tagoro in the Canary archipelago is being monitored closely by the Spanish Institute of Oceanography, together with both Canarian Universities. Submerged in October 2016, the monitoring system by RTsys will be resurfaced at the end of winter season in 2017. RTsys designed a system combining three geophones and a hydrophone. The device measures temperature, salinity and other environmental parameters.

2018:  FEB

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