Conservation of Mediterranean seascapes: analyses of existing protection schemes     

Fraschetti S  Terlizzi A  Bussotti S  Guarnieri G  D'Ambrosio P  Boero F 《Marine environmental research》2005,59(4):309-332

Marine protected areas (MPAs) are aimed at managing and protecting marine environments. Their design, however, often disregards both a thorough knowledge of the distribution of habitats and assemblages and the use of proper experimental evaluations of the efficacy of MPAs by comparing protected vs. unprotected zones. About 200 MPAs have been recently instituted in the Mediterranean area, but the evidence of their efficacy is scant. The MPA of Torre Guaceto (Southern Adriatic Sea, Italy) is one of the rare cases of effective protection enforcement. The reserve was instituted more than 10 years ago, a period currently considered as sufficient to show responses by organisms to protection. The MPA is divided into a C zone, the general reserve, where many activities are permitted, a B zone, the partial reserve where restrictions increase and two A zones, the integral reserve where access is prohibited. The goals of the paper were to map the distribution of benthic assemblages to assess if they were properly represented in the differently protected zones, and to test the efficacy of protection by quantifying possible differences between the assemblages in two control areas and in the two A zones, where human impact is completely excluded. The analysis of habitat and assemblage distribution within the MPA showed that the zones with total protection do not include most valuable environmental types. Most of the considered variables (i.e. cover of substratum, number of taxa, and average abundance of the most common taxa) were not significantly different in and out of the A zones, at each time of sampling. Results, however, suggested a possible effect of protection in modifying patterns of abundance of sponges under Cystoseira canopy (more abundant in the fully protected zone). In the subtidal habitat, differences were found in the structure of the whole assemblage and in the abundance of encrusting coralline red algae (more abundant outside the fully protected area). Notwithstanding the correct general methodology employed in the study, a lack of statistical power could have a role in preventing the detection of ecologically relevant effects of protection. In some instances, data pooling allowed a discrimination between cases where there was clearly no effect of protection and cases where there might be. On this basis, the optimization of this experimental design should be considered in further studies. In any case, if the goals of MPAs have not been clearly stated, efficacy of protection might prove very difficult to test even with the use of sound experimental designs.  相似文献   

海上净化实验舱     

C.S.Wong  W.J.Cretney  J.Piuze  P.Christensen  P.G.Berrang 《海洋科学》1982,6(1):60-62

已报道的关于大洋水中某些痕量金属的基线浓度,总的说来是随着经历的年代而一直在减少的。这样,在文献中看到的大部分有关痕量金属浓度的数据就似乎没有什么价值,而只不过是污染水平的指标罢了,因为,实验室之间精心的相互校正实践已证明,只有严格净化的采样、操作和分析技术才会产生准确的数据。  相似文献   

2万年来热带温度变化：调节半球间的气候变化     

T.P．Guilderson胡季平  陈宗团 《海洋地质前沿》1995,(1):17-19

２万年来热带温度变化：调节半球间的气候变化Ｔ．Ｐ．Ｇｕｉｌｄｅｒｓｏｎ等世界范围内因ＣＯ＿２含量倍增引起的全球温度变化估计为１°－４℃，这与热带海洋表面温度（ＳＳＴｓ）的变化非常相似。相似的热带ＳＳＴｓ变化范围（＋１°－＋３℃）显然取决于全球循环模型...  相似文献   

越南东南陆架及陆坡区油气地质调查     

K.  PГ 陈邦彦 《海洋地质》1992,(1):36-52

  相似文献   

澳大利亚海洋生物研究概况     

P.哈钦斯  吴宝铃 《海洋科学》1987,11(2):54-57

澳大利亚从事海洋生物研究的单位很多。下面我们仅扼要介绍一下其主要研究机构、经费来源及研究概况。 一、海洋生物的主要研究机构、 澳大利亚共有19所大学,主要分布在州政府所在地。除一所大学之外,这些大学都设有生物系。这些系都从事一定的海洋研究,只不过其中有些系更偏重海洋生物学研究而已。北昆士兰詹姆斯·科克大学海洋生物学在生物系享有一定地位,而其它大学在生物  相似文献   

墨西哥南下加利福尼亚上新世洛雷托盆地构造与加利福尼亚湾的演化     

P．J．Umhoefer高莉玲  张光威 《海洋地质前沿》1995,(2):15-16

墨西哥南下加利福尼亚上新世洛雷托盆地构造与加利福尼亚湾的演化Ｐ．Ｊ．Ｕｍｈｏｅｆｅｒ等洛雷托盆地滨岸部分位于南下加利福尼亚州洛雷托正北的加利福尼亚湾沿岸，面积１５×５０ｋｍ。在盆地南部，上上新统沉积岩覆于中新统火山岩之上。这些沉积物沿着盆地西南边缘洛...  相似文献   

黄、东海及其邻海的气旋与埃尔尼诺现象     

龙宝森  Howard P. Hanson 《海洋科学进展》1985,(3)

一、序言ENSO现象对全球大气环流及其伴随天气的影响,一直是近年来海气相互作用研究的焦点之一,一些有趣的研究表明,ENSO现象对中纬度气候有显著的影响.本文统计了1899-1962年每年发生在20°-40°N,120°-150°E区域(图1)以及主要气旋活动中心(图1阴影  相似文献   

亚洲的传播挤出构造：从简单的塑泥挤压实验...     

Tappo.  P 袁友仁 《南海研究与开发》1990,(4):23-31

  相似文献   

Effects of salinity and clay type on oil-mineral aggregation   总被引：3，自引：0，他引：3  

Khelifa A  Stoffyn-Egli P  Hill PS  Lee K 《Marine environmental research》2005,59(3):235-254

Effects of salinity and clay type on the aggregation process of crude oil and clay particles (oil-mineral aggregates--OMA) were studied in the laboratory. OMA were generated by shaking various oil/clay mixtures in water at 20 degrees C and at a pre-determined energy level. Shape, median and maximum sizes, size distribution and concentration of oil droplets forming OMA were measured using epi-fluorescence microscopy. Results showed that the median and maximum sizes and the concentration of mineral-stabilized droplets increase rapidly when salinity increases from zero to a critical aggregation salinity in the range of 1.2-3.5 ppt. The magnitude of the increase of droplet size is controlled by clay type, while the increase of droplet concentration is influenced by oil type. Size distributions of oil droplets are self-similar, but their magnitudes depend on salinity and oil type. The effect of salinity on droplet size distribution is strongly influenced by clay type. Empirical relationships are derived to calculate concentration and size distribution of mineral-stabilized droplets.  相似文献   

Array technology as a tool to monitor exposure of fish to xenoestrogens     

Larkin P  Folmar LC  Hemmer MJ  Poston AJ  Lee HS  Denslow ND 《Marine environmental research》2002,54(3-5):395-399

A variety of anthropogenic chemicals are capable of binding to the estrogen receptor of vertebrate species. Binding of these compounds can interfere with homeostasis by disrupting normal gene expression patterns. The purpose of this study was to investigate the feasibility of applying array technology as a monitoring tool for detecting the presence and distribution of estrogenic compounds in coastal habitats using sheepshead minnows as our model. cDNA clones that were isolated from differential display, including vitellogenin alpha and beta, vitelline envelope protein (ZP2), and transferrin, among others, were spotted on the macroarray. The results of these experiments demonstrate a characteristic expression pattern of estrogen responsive genes in sheepshead minnows exposed to 17 beta-estradiol (E2).  相似文献