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Photo-identifying seahorses

Published 2014-06-02

Off the southern tip of Portugal lays a semi-enclosed lagoon which once was home to the densest known population of seahorses in the world. Studies conducted a decade after those reports confirmed population declines in two sympatric species of 94% and 87%. Thus, seahorse conservation is of high interest in the region. Most studies estimating population densities and distributions use tagging and mark-recapture techniques that are invasive to the organism and may cause stress; a less invasive option that has been successful for several animal populations is photo-identification. Correia... (more)

Eelgrass wasting disease part deux

Published 2014-05-26

Following up with last's weeks blog, this week I will discuss a more recent study on eelgrass wasting disease that I had the opportunity to assist during field and laboratory trials. This research was recently published in the journal 'Diseases of Aquatic Organisms' by Groner et al. While epidemics of eelgrass wasting disease are less common than in the early 1900s, potentially due evolutionary changes in host resistance, seagrasses and eelgrasses are still vulnerable in many parts of the world. In the Pacific Northwest (US) there have been several areas where seagrass has declined over... (more)

Seagrass wasting disease: loosing strength

Published 2014-05-19

Zostera marina is the most abundant seagrass in North America and an ecologically important species providing coastline protection and helping to sustain livelihoods; it has also experienced devastating mortality due to disease outbreaks. In the 1930’s the endophytic protist Labyrinthula zosterae caused the world’s largest reported seagrass die-off event. This disease was termed ‘wasting disease’ and it affected populations along the Atlantic coast of North America, the European Atlantic, the North and Wadden Sea and the Baltic Sea, France, Great Britain, The Netherlands, Germany and... (more)

seaHarmony Survey

Published 2014-05-15

Whether you've used seaHarmony just a little, or a lot, we would like your input! Please help us improve seaHarmony by completing our brief survey. And enter to win a $50 Amazon gift card! (more)

Schooling fish help explain group behavior

Published 2014-05-12

In the Disney movie Finding Nemo, Marlin asks schooling moonfish for directions to Sydney during which the school makes ornate 3-D patterns resembling a sailboat, arrow and even a clownfish (mocking Marlin). While in reality, schooling fish cannot react to a conversation with another fish, nor can they create ornate patterns, they do make group decisions based on environmental cues and make rapid movements en masse. A study recently published by Kao and Couzin (PNAS 2014) explored decision making behavior in groups by developing two mathematical models of schooling fish. Early theoretical... (more)

Oil affects developing pelagic fish hearts

Published 2014-05-05

The Deepwater Horizon oil spill resulted in the release of more than 4 million barrels (636 million L) of oil at depth into the pelagic zone of an ocean ecosystem and rose to warm mixed and surface layers of the northern Gulf of Mexico between April 10 and July 14, 2010. This was unfortunately during the spawning window for many commercially import fish species, including bluefin tuna and many other large predator species (e.g., mackerel, amberjack, sailfish, marlin, mahi mahi, and other tunas). The fertilized eggs produced by all these pelagic fish are buoyant, and therefore float in the... (more)

The Phoenix Effect: a story of coral recovery

Published 2014-04-28

In a shallow sandy lagoon off Rangiroa Atoll in French polynesia, a distinctive reef habitat exists formed entirely by living giants: massive Porites coral colonies. On average, these colonies measure 2.65 meters in diameter with the largest measured colony at a whopping 7.1 meter wide - which suggests the colony is anywhere between 284-497 years old! George Roff et al. reported a remarkable recovery in Porites after the mass mortality which followed the 1997/1998 El Nino Southern Oscillation, which caused coral bleaching and death in much of the living coral tissue in Rangiroa. They have... (more)

Sponge disease dynamics and Hurricane Irene

Published 2014-04-21

Often disturbances that affect coral reef communities such as storms and disease outbreaks are assessed in response to such events, with little spatial information available to assess patterns at the scale of a patch reef. A study recently published in Plos One (title: Exploring Individual- to Population-Level Impacts of Disease on Coral Reef Sponges: Using Spatial Analysis to assess the Fate, Dynamics, and Transmission of Aplysina Red Band Syndrome (ARBS)), mapped two patch reefs in the Bahamas over the course of three years, surveying health states of individual sponges and investigating... (more)

The little (puffer) fish that could

Published 2014-04-14

This story is about mysterious circles that were found in the ocean resembling crop circles, and the mighty puffer fish who form them. While this story is not necessarily new, it is a new one to me and hopefully to some of our readers. Yoji Ookata, an underwater photographer and videographer, discovered usual formations in the sediment near Amami Oshima, one of the small islands south of mainland Japan. To his surprise, no one else had seen or could identify these patterns either. The geometric patterns were 80 feet deep and approximately 6.5 feet in diameter! After many hours of filming,... (more)

Diversity-stability hypothesis & coral reefs

Published 2014-04-07

There is an ecological theory called the diversity-stability hypothesis that posits more diverse communities are more stable, and therefore better able to resist and recover from disturbances. A recent article published in PeerJ, an open-source journal, investigated this theory in coral reef communities and found surprising results: reefs with greater species richness showed no correlation with recovery or resilience. In this meta-study, the authored compiled 41 field studies from 82 reefs to analyze changes in coral cover due to disturbance across a global gradient of species richness.... (more)