Introduction Conclusions References

Many natural streams are net heterotrophic, so I propose that trophic state be divided into autotrophic and heterotrophic state. This division allows consideration of the influence of external carbon sources as well as nutrients such as nitrogen and phosphorus. Empirical results suggest that phosphorus and nitrogen are the most important nutrients regulating autotrophic state in flowing waters ...

in this study, three stations of the north persian gulf were analyzed in order to determinethe effect of trophic levels on the concentration of harmful pahs in fish and sediment. in all cases,similar distributions were observed in which benzo(a)pyrene largely predominated andbenzo(b)fluoranthene and pyrene were the second major compounds in fish tissues. the predominantcomponents of pahs in sed...

The definition of a synthetic index for classifying the quality of water bodies is a key aspect in integrated planning and management of water resource systems. In previous works [1,2], a water system optimization modeling approach that requires a single quality index for stored water in reservoirs has been applied to a complex multi-reservoir system. Considering the same modeling field, this p...

An index (EQUATION* Estuarine QUAlity and condiTION) is presented for integrated evaluation of estuarine quality, based on an aggregation of four di!erent components: vulnerability, measuring the physical capacity of the system to react to change, water quality, which examines trophic status and eutrophication aspects, sediment quality, which looks at the sediments and benthic fauna, and tropho...

In spinal cord injuries, direct trauma by edges of sublaxated or dislocated vertebrae and indirect ischemia as a result of vascular injury necrotize the neural tissue. After spinal cord injury, tissue loss appears as micro- or macrocavitation. Accumulations of non-neuronal cells substitute spared tissue and halts axon regrowth. Lack of supporting cells (secreting trophic factors and matrix) agg...

The trophic interactions of sea urchins are known to be the agents of phase shifts in benthic marine habitats such as tropical and temperate reefs. In temperate reefs, the grazing activity of sea urchins has been responsible for the destruction of kelp forests and the formation of 'urchin barrens', a rocky habitat dominated by crustose algae and encrusting invertebrates. Once formed, these urch...

Biological invasions are becoming more common, yet the majority of introduced exotic species fail to establish viable populations in new environments. Current ecological research suggests that invasion success may be determined by properties of the native ecosystem, such as the supply rate of limiting nutrients (i.e. trophic state). We examined how trophic state influences invasion success by i...