Abstract: Fish traps and methods of using the same are disclosed. A disclosed example fish trap includes a holding chamber having an opening through which a fish may pass, and a bait chamber abutting the holding chamber and separated from the holding chamber by a water permeable barrier.

Abstract: Herein we describe crustacean fishing traps having degradable cull ring panels, as well as methods for ensuring that such traps have reduced functionality after becoming derelict. Derelict crab and lobster traps have a negative economic and ecological impact, and thus it is advantageous to use degradable traps that will lose their ability to catch and retain fish over time. Incorporating degradable cull ring panels into such traps provides an effective, economical solution. Suitable degradable cull ring panels are described herein.

Abstract: The Beaver Barrier is a unique use of rubber and steel to form a barrier that will restrict where beavers build dams without harm to animals. The material is recycled tire parts woven together which forms a tube composed of connected rings which allow water to freely pass through but restricts animals from plugging or moving the natural course of the water. This unit prevents the animals from being able to dam the flow of water.

Abstract: A fish cage having a frame structure defining an enclosure with a top and a bottom and an intersecting side. The frame is adapted to rest on the bottom of an outdoor body of water and is covered with a first netting on the top and side but not the bottom. The first netting has mesh openings sized to permit ambient water and suspended particles therein to circulate through the cage but prevent predators and competitors for food of the fish under study from entering the cage. A second netting covers the bottom of the enclosure. The second netting has second mesh openings larger than the first mesh openings and sized to prevent the fish being studied from leaving the enclosure as well as permit plant and animal life at the bottom of the body of water to enter the enclosure, thereby providing a more natural environment for the fish under study. The enclosure includes a door to permit access to the interior of the enclosure.

Abstract: A material for making marine structure comprises a rubber composition. The rubber composition contains a metal salt of .alpha., .beta.-unsaturated fatty acid and is vulcanized in a mold into a predetermined configuration. The strength of the rubber composition is anisotropic and in particular its elastic modulus is anisotropic. The direction in which the strength of the rubber composition is high is set in the direction in which stress is applied by waves. Thus, the marine-structural material is resistant to waves and tide. The rubber composition contains short fibers which are oriented in a certain direction to increase the anisotropy of the rubber composition.

Abstract: A passively anchored fishing tackle of the net kind comprises bottom nets, top nets, lateral nets, inlet nets, and lead-in nets which cooperate to form a catching space. Lateral nets, inlet nets and lead-in nets are provided with top lines with an incorporated buoyancy, and bottom sink lines. All nets of the inlet portion are square-meshed, whereas the rest is normally meshed. From both sides of the lead-in net inlet nets extend.