منابع مشابه
Predicting Postrelease Survival in Large Pelagic Fish
—Sharks, turtles, billfish, and marine mammals are frequently caught accidentally in commercial fisheries. Although conservationists and fisheries managers encourage the release of these nontarget species, the long-term outcome of released animals is uncertain. Using blue sharks Prionace glauca, we developed a model to predict the long-term survival of released animals based on analysis of smal...
متن کاملAn ODE Model of the Motion of Pelagic Fish
A system of ordinary differential equations (ODEs) is derived from a discrete system of Vicsek, Czirók et al. [Phys. Rev. Lett. 75(6):1226–1229, 1995], describing the motion of a school of fish. Classes of linear and stationary solutions of the ODEs are found and their stability explored using equivariant bifurcation theory. The existence of periodic and toroidal solutions is also proven under ...
متن کاملA length-based hypothesis for feeding migrations in pelagic fish
We evaluated the costs and benefits of long-distance horizontal migration by pelagic planktivores, Atlantic herring (Clupea harengus), blue whiting (Micromesistius poutassou), mackerel (Scomber scombrus), and capelin (Mallotus villosus) in the Norwegian and Barents seas using a numerical model and tested model predictions against field observations. Specifically, we considered (i) energetic cos...
متن کاملDoppler structure in echoes from schools of pelagic fish
The frequency distribution of energy in direct path echoes from three schools of pelagic fish is preaented. One-half-second 30-kHz CW pulses were used to study motions internal to the fish schools from distance8 up to 1200 m. The measured Doppler spread of echo enagy ranged fmm 30 Hz to 70 Hz The Doppler spread-at-side aspect is related to swimming motions by a simple algebraic model based on B...
متن کاملPelagic Fish Behaviour During Trawl Sampling Off Angola
Large sardinella (Sardinella maderensis and Sardinella aurita) in warm waters off the coast of Africa are known to be a challenge for pelagic trawl sampling, for example during acoustic surveys for abundance estimation. We observed the swimming behaviour of sardinella mixed with other pelagic species, mainly Cunene horse mackerel (Trachurus trecae), during sampling with a pelagic trawl in the c...
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ژورنال
عنوان ژورنال: Nature
سال: 1872
ISSN: 0028-0836,1476-4687
DOI: 10.1038/006142b0