A camera can accurately count freshwater fish, even in the thickest of underwater vegetation, a key finding for those who manage fisheries and control the invasive plant hydrilla, new University of Florida research shows.
The finding by UF/IFAS scientists can help researchers understand how many and which fish species are using dense plant habitats, said former UF/IFAS graduate student Kyle Wilson.
Former UF/IFAS doctoral student Andrew Barbour.
Former UF/IFAS graduate student Kyle Wilson prepares a equipment for his fish count
While cameras have been used to document fish behavior – including eating and breeding ─ this marks the first time scientists have used video to count fish in underwater plant habitats, Wilson said. In addition, no prior studies that used cameras to count fish verified their fish populations.
“It is commonly assumed that dense and invasive plants, like hydrilla, can drastically change fish habitat quality, primarily through changes in dissolved oxygen levels, water chemistry and habitat structure,” Wilson said. “Whether these changes are good or bad for fish has previously remained uncertain due to sampling problems in dense plant habitats. Using underwater cameras, we have shown that fish can and do use habitats we previously thought were too stressful for fish habitat.”
This is a big problem, especially with hydrilla, a plant that has invaded lakes throughout Florida, much of the U.S., Central America, South Africa and Australia, Wilson said. He estimated Florida spent up to $14 million per year throughout the 2000s to manage hydrilla, while the U.S. spent about $100 million per year in the 2000s for aquatic plant management.
In practical terms, researchers and conservation managers could use the UF/IFAS techniques to better understand how fish use other invasive aquatic plants as well, like Eurasian Watermilfoil, because it’s similar to hydrilla, Wilson said. Such approaches can be quite valuable in advising conservation plans and can help resolve stakeholder issues associated with these invasive plants.
“This ability to use video cameras to estimate fish abundance is a tremendous asset to fisheries management, allowing us to evaluate fish habitat use in areas where previously no sampling method was effective,” Wilson said. Australian researchers studying fish ecology have used cameras to count fish in the relatively clear waters at the Great Barrier Reef, but no research has peered through a lens to detect fish in thick vegetation like this study. “Previously, researchers that used cameras have had to make several broad assumptions that cameras work well in sampling fish. Now we know they work well.”
UF/IFAS researchers specifically focused their study on ponds with plenty of hydrilla, Wilson said, but have also conducted preliminary camera work on Lake Tohopekaliga in the Kissimmee Chain of Lakes Area.
To research his master’s thesis, Wilson lowered a camera into the water from a boat in three experimental ponds in Gainesville. He discovered the video counted freshwater fish, such as largemouth bass and bluegill sunfish – even those hidden in the nooks and crannies of hydrilla and other vegetation. Wilson counted fish during 13 weeks in the summers of 2011 and 2012, and then drained the ponds to obtain actual fish densities.
He conducted his research under the supervision of Micheal Allen, a professor of fisheries ecology at UF’s Institute of Food and Agricultural Sciences.
“We tested and verified the use of our camera techniques in extremely dense hydrilla habitats,” said Wilson, now a doctoral student in ecology at the University of Calgary.
The UF/IFAS study is published in the January issue of the journal Marine and Freshwater Research.
By Brad Buck, 352-294-3303, firstname.lastname@example.org
Sources: Kyle Wilson, 403-402-4955, email@example.com
Micheal Allen, 352-273-3624, firstname.lastname@example.org
Brad Buck | newswise
Plasma-zapping process could yield trans fat-free soybean oil product
02.12.2016 | Purdue University
New findings about the deformed wing virus, a major factor in honey bee colony mortality
11.11.2016 | Veterinärmedizinische Universität Wien
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.
The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
17.01.2017 | Earth Sciences
17.01.2017 | Materials Sciences
17.01.2017 | Architecture and Construction