Now, University of Massachusetts Amherst researcher Andy Danylchuk and colleagues from several other institutions know far more about bonefish spawning habits after using ultrasonic transmitters to tag and track bonefish movements off Eleuthera in the Bahamas. Their results appear in an early online issue of the journal Marine Biology. Results should help focus habitat conservation efforts.
It has been estimated that 30 percent of anglers who visit the Bahamas to cast for bonefish come from New England.
What Danylchuk and colleagues found by tagging these popular sport fish is that bonefish gather in schools of over 1,000 at pre-spawning aggregation sites for a few days twice a month from October to May, primarily around the new and full moon. At dusk, these large schools begin to move offshore to the edge of deep abyssal waters, over 1,000 feet deep, very unlike the shallow flats were anglers normally encounter them. There, as night falls, the fish spawn under cover of darkness.
“This is the first time movement patterns of bonefish to deep water have been formally described,” says Danylchuk, an expert on coastal fish stocks, the impact of angling and how to protect ecosystems. Although surprising, this movement to spawn in deeper water makes some sense, he adds. “One possible benefit of bonefish migrating to offshore locations to spawn is that it increases the dispersal of their fertilized eggs, especially with the high tides that happen with the new and full moons.”
Danylchuk and colleagues tagged 30 bonefish over two years, 60 in all, following them along with a few individuals previously tagged, from 2007 to 2009. Another first for this research team was observing behaviors such as porpoising, that is groups of fish leaping part-way out of the water as they travel along, they believe are likely associated with bonefish courtship. Danylchuk was amazed to see these usually bottom-hugging fish breaking the surface as they moved away from their nearshore aggregation sites.
“This new understanding of bonefish movement and spawning aggregations has significant implications for their conservation,” he says, because it establishes that pre-spawning aggregation sites identified in this study were located in transition areas between shallow coastal habitats and deep oceanic waters, the very same places that humans find desirable for marinas and tourism development.
“Knowing that bonefish are not residents of shallow flats alone means that pre-spawning aggregation sites and deeper reef habitats also need to be protected to ensure sustainable bonefish populations,” he says.
Danylchuk is familiar to many as a result of several appearances on the ESPN2 network series, “Pirates of the Flats.” This research was supported by the Bonefish and Tarpon Trust, the Patagonia World Trout Initiative, the Cape Eleuthera Institute and a number of private donors.
A short video of porpoising bonefish: www.youtube.com/watch?v=Id0vO1DUxgsAndy Danylchuk
Andy Danylchuk | Newswise Science News
Algae: The final frontier
22.06.2017 | Carnegie Institution for Science
Flipping the switch to stop tumor development
22.06.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
Germany counts high-precision manufacturing processes among its advantages as a location. It’s not just the aerospace and automotive industries that require almost waste-free, high-precision manufacturing to provide an efficient way of testing the shape and orientation tolerances of products. Since current inline measurement technology not yet provides the required accuracy, the Fraunhofer Institute for Laser Technology ILT is collaborating with four renowned industry partners in the INSPIRE project to develop inline sensors with a new accuracy class. Funded by the German Federal Ministry of Education and Research (BMBF), the project is scheduled to run until the end of 2019.
New Manufacturing Technologies for New Products
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
22.06.2017 | Physics and Astronomy
22.06.2017 | Physics and Astronomy
22.06.2017 | Materials Sciences