Effects of Sediments Nutrition Status on the Growth of Potamogeton crispus

A laboratory incubation experiment was performed to study the effects of three trophic level sediments with different nutrition status on the growth including physiological characteristics of Potamogeton crispus by embedding and suspension cultivation ways. The results showed: The high trophic level (HC) sediment was favorable for the early growth and the photosynthesis of Potamogeton crispus but unfavorable for the growth of roots. During the experiment, the POD activity rapidly increased to a maximum value under highly nutritious substrate in embedding groups. Later in the experiment, the content of soluble protein and chlorophyll decreased in the embedding group with HC sediments. To some extent, the normal growth of Potamogeton crispus was inhibited, while there wasn’t an apparente phenomenon that the decline of Potamogeton crispus.

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USE OF DISSOLVED ORGANIC MATTER BY MICROORGANISMS: FORMATION OF WATER QUALITY IN A POND OF A HIGH TROPHIC LEVEL

Fisheries ◽

10.37663/0131-6184-2020-5-25-29 ◽

2020 ◽

Vol 2020 (5) ◽

pp. 25-29

Author(s):

Anatoliy Sadchikov ◽

Sergey Ostroumov

Keyword(s):

Water Quality ◽

Organic Matter ◽

Organic Carbon ◽

Dissolved Organic Matter ◽

Trophic Level ◽

Aquatic Ecosystem ◽

High Trophic Level ◽

Bacterioplankton Community ◽

Algae And Bacteria

The role of algae and bacteria in the consumption and mineralization of dissolved organic matter (DOM) in a highly trophic aquatic ecosystem was studied. The phytoplankton and bacterioplankton community consumed 60% of added DOM in August and 56% of DOM in September. Of the uptaken DOM, a significant amount of organic carbon was mineralized. In August 42.7% and in September 29% of organic carbon (of the consumed organic matter) were used for respiration.

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Fishing through (and up) Alaskan food webs

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f08-207 ◽

2009 ◽

Vol 66 (2) ◽

pp. 201-211 ◽

Cited By ~ 14

Author(s):

Michael A. Litzow ◽

Daniel Urban

Keyword(s):

Time Series ◽

Trophic Level ◽

High Trophic Level ◽

Climate Index ◽

Climate Regime ◽

Fisheries Sustainability ◽

Competing Hypotheses ◽

Mean Trophic Level ◽

Highly Correlated ◽

Historical Periods

We used a 112-year time series of Alaskan fishery catches to test competing hypotheses concerning trends in mean catch trophic level, a widely used indicator of fisheries sustainability. We found that mean trophic level has generally remained steady or increased in recent decades on Alaska-wide and regional scales, indicating stable catches of high trophic level taxa. During historical periods of declining mean trophic level, catches of upper trophic level taxa either increased or remained steady, contrary to the predictions of the “fishing down the food web” hypothesis. Further, a climate index was highly correlated (r = 0.69–0.97) with mean trophic level and (or) the related fisheries in balance (FIB) index across climate regime shifts in the 1940s and 1970s, indicating that climate effects, particularly on high trophic level taxa, can act as the major driver of variability in these parameters. These results provide a contrast to the view of ubiquitous declines in mean trophic level of fishery catches, driven by overexploitation and serial stock replacement.

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Fireproof killer whales (Orcinus orca): flame-retardant chemicals and the conservation imperative in the charismatic icon of British Columbia, Canada

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f05-244 ◽

2006 ◽

Vol 63 (1) ◽

pp. 224-234 ◽

Cited By ~ 41

Author(s):

Peter S Ross

Keyword(s):

British Columbia ◽

Trophic Level ◽

Polybrominated Diphenyl Ethers ◽

Marine Mammals ◽

Polychlorinated Biphenyl ◽

High Trophic Level ◽

Orcinus Orca ◽

Weight Of Evidence ◽

Older Individuals ◽

Killer Whales

Long-lived and high trophic level marine mammals are vulnerable to accumulating often very high concentrations of persistent chemicals, including pesticides, industrial by-products, and flame retardants. In the case of killer whales (Orcinus orca), some of the older individuals currently frequenting the coastal waters of British Columbia (BC) were born during the First World War, well before the advent of widespread chemical manufacture and use. BC's killer whales are now among the most polychlorinated biphenyl (PCB) contaminated marine mammals in the world. While the "legacy" PCBs have largely been banned, polybrominated diphenyl ethers (PBDEs) have recently emerged as a major concern. The endocrine-disrupting nature of these two persistent fire retardants in biota spells trouble at the top of the food chain, with increasing evidence of effects on reproductive health, the immune system, and development in exposed mammals. The heavy contamination of BC's killer whales, coupled with their long life span and high trophic level, highlights the need for a "weight of evidence" approach in research, conservation planning, and regulatory decisions. Given the global nature of contaminant dispersion, such approaches can only be effective when carried out on both national and international scales.

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Historical changes in mean trophic level of southern Australian fisheries

Marine and Freshwater Research ◽

10.1071/mf13246 ◽

2014 ◽

Vol 65 (10) ◽

pp. 884 ◽

Cited By ~ 5

Author(s):

Heidi K. Alleway ◽

Sean D. Connell ◽

Tim M. Ward ◽

Bronwyn M. Gillanders

Keyword(s):

Trophic Level ◽

Spatial Data ◽

South Australia ◽

Trophic Levels ◽

High Trophic Level ◽

Fishing Pressure ◽

Time Line ◽

The Mean ◽

Mean Trophic Level ◽

Catch Statistics

Decreases in the mean trophic level (MTL) of fishery catches have been used to infer reductions in the abundance of high trophic level species caused by fishing pressure. Previous assessments of southern Australian fisheries have been inconclusive. The objectives of the present study were to provide more accurate estimates of MTL using disaggregated taxonomic and spatial data. We applied the model of MTL to fisheries catch statistics for the state of South Australia from 1951 to 2010 and a novel set of historical market data from 1936 to 1946. Results show that from 1951 to 2010, MTL declined by 0.16 of a trophic level per decade; a rate greater than the global average of 0.10 but equivalent to similar regional investigations in other areas. This change is mainly attributable to large increases in catches of sardine, rather than reductions in the catches of high trophic level species. The pattern is maintained when the historical data is included, providing a time line from 1936 to 2010. Our results show a broadening of the catch of lower trophic levels and suggest care in interpretation of MTL of catches because reductions do not necessarily reflect change in high trophic level species by fishing pressure.

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Influence of some commercial proteases and enzymatic associations on the hydrolytic solubilization of deboned poultry meat proteins Influencia de algunas proteasas comerciales y preparados enzimáticos en la solubilización hidrolitica de las proteínas de la carne de pollo separada mecánicamente

Food Science and Technology International ◽

10.1177/108201320000600404 ◽

2000 ◽

Vol 6 (4) ◽

pp. 301-306 ◽

Cited By ~ 7

Author(s):

L.H. de Barros Soares ◽

D. Ney Marques ◽

P. Melchionna Albuquerque ◽

M.A. Záchia Ayub

Keyword(s):

Soluble Protein ◽

Proteolytic Enzymes ◽

Poultry Meat ◽

Initial Amount ◽

Maximum Value ◽

Initial Ph ◽

Basic Source ◽

Proteolytic Activities ◽

Fungal Protease ◽

Hydrolysis Of

Mechanically deboned poultry meat (MDPM) was used as a basic source of protein to assess the efficiency of seven proteolytic enzymes and some enzymatic associations over the hydrolysis of that protein. As a main parameter, the evolution of protein solubilization during 4 h of proteolysis was evaluated. The enzymes alcalase, esperase, flavourzyme, fungal protease, HT-proteolytic, papain, proteopex, and combinations of alcalase + flavourzyme, esperase + flavourzyme, HT-proteolytic + flavourzyme, and proteopex + flavourzyme were applied at concentrations of 0.60% and 1.20% of commercial product as a function of total protein. The initial pH was adjusted to 7.0 or 8.0 and the temperature was maintained at 50 °C or 60 °C according to optimal conditions for each enzyme. The proteolytic activities of the enzymes were also compared with azocasein. The hydrolysis index (HI), i.e., the rate between the maximum value and the initial amount of soluble protein was formulated to allow the comparison among treatments. Results showed that the temperature did not influence the proteolysis in the tested model. The association of alcalase + flavourzyme was shown to be more efficient than all other treatments, obtaining more than 70% of soluble protein. Fungal protease pre sented the lowest results.

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