Posts Tagged: environmental science

Meet Yoko Iwamoto

Meet Yoko Iwamoto

  Water is an all-encompassing part of Yoko Iwamoto’s life. She grew up by the sea, influencing her decision to study the ocean. Her studies have taken her as far north as the Bering Sea and as far south as the Equator. Now a marine chemist at Hiroshima University, Iwamoto studies the interaction between Earth’s oceans and atmosphere – and what this means for climate change.   What was your first time on a boat like? My first time was in Kure, where I was born. Kure is a seaside town south of here known for its shipbuilding. My family relatives had a boat. A very small boat — it… Read more

Hopping to the Frontier: Following a frog’s evolutionary movements

Hopping to the Frontier: Following a frog’s evolutionary movements

  A common species of Asian tree frog may actually be two separate species according to new genetic data collected by an international group of scientists.  If the two groups of frogs are confirmed to be different species, assigning their scientific names may require searching historical records of foreign explorers in Japan during the 1800s. Before the frogs are officially recognized as two separate species, researchers will test if individual frogs from the two groups have unique physical or behavioral features and if they can produce healthy offspring. The project began when researchers at European universities expanded their studies on sex determination and population dynamics in amphibians to include Asian… Read more

Japanese Tadpoles Relax in Hot Springs

Japanese Tadpoles Relax in Hot Springs

One type of juvenile frog can survive in hot onsen water Japanese tadpoles can live and grow in natural hots springs, or onsen, with water temperatures as high as 46.1oC (115oF).  Living in onsen may benefit the tadpoles’ immune systems, speed their growth, and allow the tadpoles to survive on small volcanic islands where there are few other natural sources of fresh water.   Tadpoles of the same frogs were previously found living in hot springs in Taiwan and other Japanese islands, but this field study found tadpoles living in the hottest ever recorded temperatures for any amphibian tadpole.  The research was completed by scientists at Hiroshima University with collaborators… Read more

How many organisms do live in this aquatic habitat?

How many organisms do live in this aquatic habitat?

Environmental DNA survey surrounding you     The aim of this new measurement method is to estimate the distribution of aquatic animals using droplet digital polymerase chain reaction (ddPCR) in order to quantify the number of target DNA copies present. This method focuses on quantification accuracy for low environmental DNA (eDNA) concentrations, because the eDNA recovered for target species from field samples typically occur in very low concentrations. This technique can be applied for habitat research on rare or non-native species in the field. Evaluations of species distribution and biomass are fundamental in studies on the population dynamics and community structure of an ecosystem. Recently, the eDNA method was developed… Read more

What are the mechanisms of zooxanthella expulsion from coral?

What are the mechanisms of zooxanthella expulsion from coral?

Coral bleaching, which often results in the mass mortality of corals and in the collapse of coral reef ecosystems, has become an important issue around the world, with the number of coral reefs decreasing annually. Associate Professor Kazuhiko Koike and Ms. Lisa Fujise of the Graduate School of Biosphere Science at Hiroshima University and their collaborators have proposed mechanisms that might cause coral bleaching and damage. This research group demonstrated that corals more actively digest and expel damaged symbiotic zooxanthellae under conditions of thermal stress, and that this is likely to be a mechanism that helps corals to cope with environmental change. On the other hand, if the stressful conditions… Read more