In this paper, we present a simple theoretical, steady-state equilibrium, predator-prey model for the joint management of marine mammals and fish species. As an empirical case, choose cod grey seals in Nordic-Baltic Sea countries, several benefits costs related to latter are considered. We show that optimal seal population is much lower than actual population, result robust variations relevant ...

Background: Aquatic plants are an important component of aquatic ecosystems. They are valuable for the oxygen and carbon dioxide household and generate habitats especially for small fish and other small organisms. However, problems for the maintenance of water bodies can result from mass occurrences of these plants. Invasive neophytes such as members of the Elodea genus are particularly problem...

BACKGROUND Lethargic Crab Disease (LCD) has caused significant mortalities in the population of Ucides cordatus crabs in the Mucuri estuary in Bahia State, Brazil, and has brought social and economic problems to many crab-harvesting communities that depend on this natural resource. The present work examined the perceptions of members of a Brazilian crab harvesting community concerning environme...

rice is one of the most important staple cereals‏ ‏in iran and has a main role in providing ‎the food ‎security. harvesting by hand postpone the rice harvesting stage, and facing late season ‎rainfall, and increase of yield losses during harvesting. to determine the most suitable ‎harvesting method in gilan, three different harvesting methods (by hand, harvester and ‎combine) were considered as...