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Tarpon Springs, FL, United States

Hadley N.H.,South Carolina Department of Natural Resources | Hodges M.,South Carolina Department of Natural Resources | Wilber D.H.,College of Charleston | Coen L.D.,Marine Laboratory
Restoration Ecology

Eastern oyster (Crassostrea virginica) habitat is increasingly being restored for the ecosystem services it provides rather than solely as a fishery resource. Community-based projects with the goal of ecological restoration have successfully constructed oyster reefs; however, the habitat benefits of these restoration efforts are usually not assessed or reported. In this study, we examined oyster habitat development at five community-based oyster restoration sites in South Carolina using oyster population parameters, resident fauna densities, and sedimentation (percent sediment coverage) as assessment metrics. All sites included multiple-aged reefs (1-3 years old) at the time of the fall 2004 sampling. Resident crabs and mussels were abundant at all five sites and crab assemblages were related to the size structure of the oyster microhabitat. Scorched mussel (Brachidontes exustus) abundances were most frequently correlated with oyster and other resident species abundances. Associations among oysters and resident crabs and mussels were not evident when analyses were conducted with higher level taxonomic groupings (e.g., total number of crabs, mussels, or oysters), indicating that species-level identifications improve our understanding of interactions among reef inhabitants and oyster populations. Community-based restoration sites in South Carolina provide habitat for mussels and resident crabs, in some cases in the absence of dense populations of relatively large oysters. Monitoring programs that neglect species-level identifications and counts of mussels and crabs may underestimate the successful habitat provision that can arise independent of large, dense oyster assemblages. © 2009 Society for Ecological Restoration International. Source

Harris R.J.,Florida Gulf Coast University | Milbrandt E.C.,Marine Laboratory | Everham III E.M.,Florida Gulf Coast University | Bovard B.D.,Florida Gulf Coast University
Estuaries and Coasts

The effects of reduced tidal flushing on post-hurricane mangrove recovery were measured across a gradient of hurricane disturbance (in order of decreasing wind intensity: Captiva, North Sanibel, Central Sanibel, and East Sanibel). Each region consisted of replicate study plots with either reduced tidal exchange (tidally restricted location) or an open tidal connection (tidally unrestricted location). Locations with reduced tidal exchange displayed significantly lower (two-way ANOVA, p ≤ 0.0001) tidal amplitude, decreased seedling densities, and decreased productivity (recruitment, growth, and litter fall) when compared to the tidally unrestricted locations. Results also indicated significant regional variations in measures of mangrove stand structure (seedlings and canopy) and productivity (recruitment, growth, and litter fall) up to 4-years post-hurricane disturbance. These findings suggest that the legacy effects from hurricane disturbance vary with degree of wind intensity, acting both independently and synergistically with the effects of tidal restriction to influence post-hurricane mangrove structure and function. © 2010 Coastal and Estuarine Research Federation. Source

Crawled News Article
Site: http://phys.org/biology-news/

The research, from the University's Institute of Marine Science, led by Master's student Lucy van Oosterom and including Dr Craig Radford and Professors John Montgomery and Andrew Jeffs, is the first direct evidence that fish communicate to maintain group cohesion. While scientists have known fish send messages to each other for mating purposes or to defend territory, this is the first time research has proved they also use contact calls to keep together. The research team used captive wild Bigeyes (Pempheris adspersa) in the study, a species commonly found along New Zealand's north-east coast. Bigeyes are generally nocturnal, retreating to caves during the day and foraging at night in loosely-knit shoals. Previous work by Dr Radford has shown Bigeyes have a distinctive 'pop' call with an estimated maximum range of 31.6m. This vocal behaviour, coupled with relatively sensitive hearing organs, led researchers to assume Bigeyes communicated in groups but up to now the evidence has been anecdotal. Using underwater hydrophones, a GoPro camera and an MP3 player, the researchers collected almost 100 fish from the Leigh coast north of Auckland and put them in saltwater tanks at Leigh Marine Laboratory. In experiments carried out over five months, they played two types of sound to the captive fish: one of the normal reef environment at Leigh where the fish live, and another recording of Bigeye vocalisations. When the sound recordings were played, the Bigeyes increased their own calling rates by more than five times in order to maintain contact over and above the background noise. They also swam closer together. When there were no sound, the fish swam further apart. "This study means that fish are now the oldest vertebrate group in which this behaviour has been observed and that has interesting implications for our understanding of evolutionary behaviour among vertebrates," Ms van Oosterom says. Explore further: Fish talk to each other, researcher finds More information: L. van Oosterom et al. Evidence for contact calls in fish: conspecific vocalisations and ambient soundscape influence group cohesion in a nocturnal species, Scientific Reports (2016). DOI: 10.1038/srep19098

Crawled News Article
Site: http://www.scientificamerican.com

Author’s note: This is the latest post in the Wonderful Things series. You can read more about this series here. Opossum shrimp leeches combine three concepts that do not seem to belong together into one awesome parasite -- a parasite that also happens to be one-quarter of the size of its host: In human terms, this would be a parasite the length of your lower leg. It’s definitely a drag for the opossum shrimp. This is an opossum shrimp: Opossum shrimp get their name from their habit of brooding their non-swimming larvae in a special pouch, and from their obvious resemblance to shrimp. They are not, however, actual shrimp. There are only two species of the ambitious leeches who target them. The first described species – Mysidobdella borealis -- was discovered on opossum shrimp around the Arctic and North Atlantic Ocean around Spitzbergen, the White Sea, the Kara Sea, Greenland, and as far south as New Jersey and France. The newer of the two species – Mysidobdella californiensis -- was discovered, not surprisingly, off the coast of California. A freak event led to its discovery: a bloom of opossum shrimp – also called mysids – in 2010. For reasons not understood by anyone, in the summer and fall of 2010, the population of opossum shrimp in the Pacific off California exploded, an event that biologists perhaps euphemistically termed a “reproductive swarm”. At the Bodega Marine Laboratory in Bodega Bay, California, so many mysids appeared that they were sucked into the filtration chambers of the lab’s water clarification system. The staff, making the most of the windfall, simply collected them for fish food. However, the staff, ever observant, happened to notice something … odd. Some of the mysids were sporting rather large groupies. The staff made “additional efforts” to collect opossum shrimp with hitchhikers directly from the filters. They succeeded on only one day over the next two weeks, but that was enough to seal the deal. Both species of opossum shrimp leech look a bit like a skinny cheese doodle surmounted by an “oral sucker”. The new species, M. californiensis, has a much larger and more “deeply cupped” oral sucker than M. borealis. They also have tail suckers, and M. californiensis’s is also about twice the size of M. borealis’s. It’s likely these leeches are parasites specific to opossum shrimps. In one of the creepier passages in the text, the authors noted, “In the laboratory, leeches rapidly attached to mysids with the oral sucker upon contact and then shifted to a position dorsally or laterally on the cephalothorax or abdomen.” Have I mentioned lately how much I love my fingers and thumbs? Additionally, no fish red blood cells have been found in their guts. On the other hand, mysid hemolymph (blood) has not yet been confirmed in their gut either. M. borealis also apparently turns its nose up at every local fish it’s been offered, and like M. californiensis, loves to cuddle with mysids. Strong circumstantial evidence, but circumstantial nonetheless. Although these opossum shrimp leeches are the only marine leeches strongly suspected to parasitize invertebrates, marine leeches are apparently commonly found on lots of other inverts. For these other invertebrates, picking up a marine leech seems to be likliest in sand and mud. However, these leeches are not parasitizing the arthropods they shack up with there; they have never been found to suck their hemolymph either. Instead, they seem to use their shells as a surrogate floor on which to anchor themselves or attach a cocoon, a leech egg case. The leeches’ true victims are fish or sea turtles in the surrounding waters, who no doubt wish their parasites would follow the example of the opossum shrimp leeches, and see the real appeal of shrimp sushi. Burreson, Eugene M., Bernard Kim, and Julianne Kalman Passarelli. "A New Species of Mysidobdella (Hirudinida: Piscicolidae) from Mysids along the California Coast." Journal of Parasitology 98, no. 2 (2012): 341-343.

Crawled News Article
Site: http://www.chromatographytechniques.com/rss-feeds/all/rss.xml/all

Scientists from the University of California, Davis, are deploying "robot larvae" into the ocean at Bodega Bay, just north of San Francisco. These robots mimic clouds of microscopic marine larvae, such as baby crabs, mussels, clams and rockfish. The data the bots bring back provide some of the first direct confirmation of a decades-old and surprisingly contentious scientific mystery: Where do marine larvae go, how do they get there and back and what allows them to do this? The research carries implications for a range of issues, including managing marine protected areas, fisheries, invasive species and the impacts of climate change. "How can you effectively manage something if you do not know where it goes, how it got there and how it gets back?" said project lead scientist Steven Morgan, a professor of marine ecology with the UC Davis Bodega Marine Laboratory and the Department of Environmental Science and Policy. "The fate of larvae has been a mystery since they were discovered. If you think about yourself, you always know where your kids are and exactly how many are alive, right? It's really fundamental information." A single female marine organism can release hundreds or thousands of larvae at once. For a century, the prevailing thought was that after the larvae were born, they would drift out to sea much like the seeds from a dandelion flower, with little to no control of their movements. To survive was to win the lottery—only the lucky few could withstand the rough and tumble of the wild ocean and grow to make it back to their adult homes. The idea, though widespread, has gone untested because scientists cannot track microscopic larvae as they develop for weeks while being transported by currents. The lottery idea never made sense to Morgan, however. He had to bridge disciplines, receiving formal training in fields that do not always come together—oceanography and ecology, evolution and behavior—to investigate the discrepancy between what he was reading in his textbooks and what made sense to him. Looking somewhat like Minions, the robots' bodies are fire extinguisher cylinders painted bright yellow. Skirtlike white fan blades at their "waists" make them spin as they rise or sink, and a gyro inside estimates vertical speed. Sprouting from their black-capped tops are LEDs and a pinger for tracking, and antennas, GPS and satellite communications. Environmental sensors log salinity, temperature, light, depth and swimming speed. The robots, officially called Autonomous Behaving Lagrangian Explorers, or ABLEs, are programmed to behave like a group of larvae throughout their development. Nine of them are currently being deployed by the research team. They were built by Tom and Donna Wolcott, professors emeritus from North Carolina State University. In the late 1980s, the Wolcotts wondered how larvae of Bermuda's land crabs got back to these isolated islands. "We could track adult land crabs with radio transmitters, but not microscopic larvae in the sea," said Tom Wolcott. "We thought, 'What if we had something that behaves like a larva, but that we can track?' The first 'smart drifters' planted seeds when Dr. Morgan saw them in a swimming pool at a conference. Once they'd evolved to be easily trackable, as well as realistically mimicking behavior of larvae, the stage was set for this collaboration." Morgan also reached out to UC Davis oceanographer John Largier, who has been working to map the water flow patterns that larvae can exploit in coastal upwelling regions, such as those off California. The robot larvae, which Morgan and his colleagues have been deploying for hours or days at a time, reveal that larvae control their movements by swimming vertically. They also stay much closer to the shoreline than expected. Larvae of most species go only a mile from shore rather than far out to sea, as was once thought. They move up and down in the water column and return toward the shore using currents like a conveyor belt. Most stay below the strong surface currents to avoid getting carried out to sea. "People have a hard time believing that microscopic larvae control their movements in strong currents because they're so small," said Morgan. "People can't get over the fact that they are designed evolutionarily to do this." Rick Grosberg, director of the UC Davis Coastal and Marine Sciences Institute and a professor of evolution and ecology, has also spent much of his career studying marine larvae. "At this point, I can tell you pretty much where a larva came from," Grosberg said. "But I can't tell you how it got there. I have no idea. There's this pervasive belief that larvae are pathetic and there's very little they can do to control their fate. Morgan's work is the first serious step in the complex world of the coastal ocean to show that is not so. "Imagine the days before cell phones and GPS, and your kid says, 'I went straight home after school.' You had to believe it because you really didn't have an option. Now parents have options and so—at last—do marine scientists."

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