How can tropical coral reefs be protected effectively? An international team of 37 scientists from around the world studied nearly 1,800 coral reefs to determine the effectiveness of protective measures in areas with varying degrees of human influence. The study comprises data collected over a period of nine years and was published this week in the renowned journal Proceedings of the National Academy of Sciences.
With his research on coral reefs off the Indonesian island of Sulawesi, reef ecologist Dr. Sebastian Ferse from the Leibniz Centre for Tropical Marine Research (ZMT) contributed to the study. “We have been able to show that the influence of humans in the vicinity of the managed areas determines which goals of protection are achieved,” reports Ferse.
Coral reef with plenty of fish in a National Park off Thailand.
Photo: Melanie Bon, Leibniz Centre for Tropical Marine Research
Protected areas in areas with high human impacts had only a quarter of the fish biomass compared to those in regions far from human influence. Reasons include illegal fishing and fish swimming across the boundaries of the protected zones into areas freely accessible to fishermen.
The scientists also compared protected and unprotected areas along varying degrees of human influence. “This allowed us to find out under which conditions protective measures have the greatest effect,” says Sebastian Ferse.
In regions with high human impacts, researchers found up to five times more fish biomass in protected areas than in reefs where fishing was not restricted. For most fish species, the highest effect of protection can be achieved where humans already have a fairly strong influence on the reefs. The adjacent marine areas also benefit from fish growing up in protected areas but spilling over to neighbouring reefs.
However, for the big predatory fish, such as sharks and large groupers, the results looked different. The probability of encountering these predatory fish in the protected areas at places with high human pressure was a hundred times lower than in areas far from human influence. About 200 dives were necessary to see one of the big predatory fish, but in remote places they were encountered on almost every second dive.
“This is due to the fact that large predatory fish also roam over large areas and therefore swim beyond the boundaries of the protected zone more frequently,” says Ferse. “In addition, fishing usually selectively targets the largest species, so they are also the first to be decimated”. So, according to Ferse, when it comes to protecting large predatory fish such as sharks, protection efforts are best focused on the more remote areas.
In many locations it is not realistic to enforce protected areas with a complete ban on fishing due to the local social, economic and cultural conditions. “In the study, we therefore also examined the effectiveness of fishing restrictions, which, for example, only permits selected fishing methods,” explains Sebastian Ferse.
The results were encouraging. Although the effect of partial restrictions was not as great as with complete protection, there was significantly more fish biomass in these areas than in those with no restrictions at all. “Such a concept of protection is usually easier to accept and represents a compromise,” says Ferse.
The research results point to the trade-offs between conservation objectives such as protection of large predators or maximizing fishable biomass. They thus provide environmental managers with tangible information on tailored management approaches to meet specific objectives under particular local conditions.
The study titled "The gravity of human impacts mediates coral reef conservation gains" was published online this week in the journal Proceedings of the National Academy of Sciences: www.pnas.org/cgi/doi/10.1073/pnas.1708001115
Dr. Sebastian Ferse
Leibniz Centre for Tropical Marine Research (ZMT)
Phone: 0421 / 23800-28
Dr. Susanne Eickhoff | idw - Informationsdienst Wissenschaft
Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY
NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences