Marine cage culture and the environment: twenty-first century science informing a sustainable industry

Technological innovation has made it possible to grow marine finfish in the coastal and open ocean. Along with this opportunity comes environmental risk. As a federal agency charged with stewardship of the nation’s marine resources, the National Oceanic and Atmospheric Administration (NOAA) requires tools to evaluate the benefits and risks that aquaculture poses in the marine environment, to implement policies and regulations which safeguard our marine and coastal ecosystems, and to inform production designs and operational procedures compatible with marine stewardship. There is an opportunity to apply the best available science and globally proven best management practices to regulate and guide a sustainable United States (U.S.) marine finfish farming aquaculture industry. There are strong economic incentives to develop this industry, and doing so in an environmentally responsible way is possible if stakeholders, the public and regulatory agencies have a clear understanding of the relative risks to the environment and the feasible solutions to minimize, manage or eliminate those risks. This report spans many of the environmental challenges that marine finfish aquaculture faces. We believe that it will serve as a useful tool to those interested in and responsible for the industry and safeguarding the health, productivity and resilience of our marine ecosystems. This report aims to provide a comprehensive review of some predominant environmental risks that marine fish cage culture aquaculture, as it is currently conducted, poses in the marine environment and designs and practices now in use to address these environmental risks in the U.S. and elsewhere. Today’s finfish aquaculture industry has learned, adapted and improved to lessen or eliminate impacts to the marine habitats in which it operates. What progress has been made? What has been learned? How have practices changed and what are the results in terms of water quality, benthic, and other environmental effects? To answer these questions we conducted a critical review of the large body of scientific work published since 2000 on the environmental impacts of marine finfish aquaculture around the world. Our report includes results, findings and recommendations from over 420 papers, primarily from peer-reviewed professional journals. This report provides a broad overview of the twenty-first century marine finfish aquaculture industry, with a targeted focus on potential impacts to water quality, sediment chemistry, benthic communities, marine life and sensitive habitats. Other environmental issues including fish health, genetic issues, and feed formulation were beyond the scope of this report and are being addressed in other initiatives and reports. Also absent is detailed information about complex computer simulations that are used to model discharge, assimilation and accumulation of nutrient waste from farms. These tools are instrumental for siting and managing farms, and a comparative analysis of these models is underway by NOAA.

藻胆体的光谱特性光能传递

1．对嗜热蓝藻层理鞭枝藻(Mastigocladus laminosus)藻胆体的光谱特性和光能传递进行了研究。其完整藻胆体的吸收峰位于622 nm，室温荧光发射峰位于673 nm。在77K荧光发射光谱中，完整藻胆体的荧光峰只有一个，位于685 nm，是末端发射体1的荧光。在低浓度磷酸缓冲液中发生严重解离的藻胆体，其77K荧光发射光谱中有二个发射峰和一个发射肩。两个荧光发射峰分别位于644 nm和683 nm。前者为主峰，属于C-藻蓝蛋白的荧光，后者是次峰，属于末端发射体2的荧光。荧光发射肩位于660 nm附近，属于别藻蓝蛋白的荧光。据此，提出层理鞭枝藻藻胆体光能传递途径如下： 藻红蓝蛋白→c—藻蓝蛋白→别藻蓝蛋白→端发射体l、末端发射体2： 2．对嗜热蓝藻层理鞭枝藻藻胆体—类囊体膜的光谱特性和光能传递进行了研究。在吸收光谱中，其藻胆体——类囊体膜在可见光区域有5个峰，它们分别位于420 nm、438 nm、490 nm、624 nm和678 nm。420 nm、438 nm和678 nm为叶绿素a的吸收峰位置。490 nm是类胡罗卜素的吸收峰，624 nm是藻胆体的吸收峰。对藻胆体——类囊体膜用580 nm波长的光激发藻胆蛋白时，在室温荧光发射光谱中有一个发射峰和一个发射肩，分别位于657 nm和690 nm，前者属于藻胆蛋白的荧光，后者属于叶绿素a的荧光。这说明藻胆蛋白能将捕获的光能传递给类囊体膜上的叶绿素a。在77K荧光发射光谱中有4个峰，它们分别位于649 nm、660 nm、688 nm和730 nm。前二者属于藻胆蛋白的荧光，后二者属于叶绿素a的荧光。这同样说明藻胆蛋白能将捕获的光能传递给类囊体膜上的叶绿素a。当用436 nm波长光激发叶绿素a时，藻胆体——类囊体膜的室温荧光发射光谱中有两个荧光峰出现，位于685 nm的峰来源于光系统Ⅱ，位于713 nm的峰来源于系统I。这说明叶绿素a捕获的光能不能逆传递给藻胆体中的藻胆蛋白。在77K荧光发射光谱中也只有叶绿素a的荧光峰，位于695 nm的峰来源于光系统Ⅱ，位于730 nm的峰来源于光系统l。此结果同样说明叶绿素a捕获的光能不能逆传递给藻胆蛋白． 3．我们以多变鱼腥藻(Anabaena variabilis)为材料，对其藻胆体核心和藻蓝蛋白进行了重组实验，得到了具有光能传递效率的藻胆体核心——藻蓝蛋白复合物。在吸收光谱中，藻胆体核心有一吸收峰和一个吸收肩，分别位于654 nm和600 nm。藻蓝蛋白的吸收光谱中只有一个峰，位于620 nm．重组样品的吸收光谱有一吸收峰和一吸收肩，分别位于654 nm和620 nm．由于620 nm与654 nm的吸收比远大于核心的600 nm与654 nm的吸收比，因此，可以认为部分藻蓝蛋白已与核心重组。在室温荧光发射光谱中，藻胆体核心只有一个峰，位于676 nm。藻蓝蛋白只有一个峰，位于653 nm。重组样品有一荧光发射峰和一荧光发射肩，分别在669 nm和650 nm附近。669 nm荧光来源于核心，650 nm荧光来源于藻蓝蛋白。重组后的核心的650 nm荧光显著大于未重组的核心，这也说明部分藻蓝蛋白与核心已重组．在77K荧光发射光谱中，藻蓝蛋白只有一个峰，位于655 nm。藻胆体核心有二个峰，分别位于666 nm和686 nm。重组样品有两个荧光发射峰和一荧光发射肩，分别位于666 nm、683 nm和648 nm附近．重组的核心的别藻蓝蛋白的荧光(F666)和藻蓝蛋白的荧光(F648)都强于未重组的核心。这一结果同样说明有藻胆体——藻蓝蛋白复合物生成。 除以上研究工作之外，我们还对多变鱼腥藻藻胆体在解离过程中的光谱特性及光能传递、藻胆体——类囊体膜的光谱特性及光能传递、藻胆体解离重组、藻胆体核心在低浓度磷酸缓冲液中的光谱特性、以及温度对藻胆体核心的影响等进行了研究。研究结果有待整理。 本文编写：PBS：藻胆体;PEB：藻红胆素;PE：藻红蛋白;PUB:藻尿胆素;PEC：藻红蓝蛋白;PCB:藻蓝胆素;PC：藻蓝蛋白;PSⅡ：光系统Ⅱ;APC:别藻蓝蛋白;PS I：光系统I;TE:末端发射体

Preliminary observations on the morphometric characteristics, length weight relationship, food and fedding habits and fecundity of Saurida tumbil (Bloch) off Bombay coast

Fifteen morphometric and four meristic characters of Saurida tumbil were studied and their relationships with total length and head length were established. The length weight relationship worked out to be W= -5.6055 L(super)3.291. The fish is a carnivore, feeding mainly on small fishes, molluscs and crustaceans. Larger fishes are selective feeders on fish. It is a long protracted spawner. Fecundity varied from 6008 to 17384 eggs in specimens of size group 212-420 mm. Fecundity-total length, fecundity-total weight of fish and fecundity - total weight of ovary relationships were worked out to be F=0.9414 L(super)1.6626, F=180.7069 W(super)0.7531 and F=3153.0375 W(super)0.8278 respectively.

Some examples of multiple solutions in limiting flaw calculations using PD6493:1991 fracture mechanics analyses

The use of PC-based PD6493:1991 fracture assessment procedures has revealed that, under certain circumstances, flaws of different dimensions may be found as being limiting or critical for identical applied conditions. The main causes for multiple solutions are a steep applied stress gradient, residual stress relaxation and flaw re-characterisation. This work uses several case studies to illustrate some of the circumstances under which multiple solutions occurs.

A markov chain Monte Carlo method for estimating population mixing using Y-chromosome markers: Mixing of the Han people in China

We present a new approach for estimating mixing between populations based on non-recombining markers, specifically Y-chromosome microsatellites. A Markov chain Monte Carlo (MCMC) Bayesian statistical approach is used to calculate the posterior probability