Trading and transport by sea goes back to prehistoric times. Stone Age settlements and canoes, Viking ships, medieval cogs, fluyts, tall ships, warships, defence systems, jetties, harbour installations and aircraft wrecks—Denmark has got it all.
Since at least the 1970s, researchers have suspected that the elasmobranchs—a group of fish containing sharks, rays, skates, and sawfish—can detect magnetic fields. But up till now, no one had shown that sharks use the fields to locate themselves or navigate.
By exposing sharks to certain magnetic cue, researchers from Florida State University have now managed to demonstrate not only that sharks have an ability to detect Earth’s magnetic field but moreover that they are able to use it to travel long distances with accuracy.
Researchers led by Louisiana State University (LSU) alumna Joanna Griffiths from Portland, Oregon, and her faculty advisor LSU Department of Biological Sciences Associate Professor Morgan Kelly reveals why some oysters may be more resilient to freshwater than others.
Griffiths wanted to find out whether, due to transgenerational plasticity, oysters that lived in low salinity would have offspring that was more resistant to low salinity.
Transgenerational plasticity occurs when a generation’s flexibility is passed on to the next generation.
When Lisa Carne first visited Laughing Bird Caye National Park in 1994, the reef was vibrant and bursting with life, abundant with fish, corals, lobsters, crabs, sponges and sea turtles. After the hurricane, it was a scene of desolation, the seabed a swathe of rubble dotted with a few surviving corals. Hurricane Iris not only killed corals but uprooted their structure, making recovery more difficult.
