广东沙扒潮汐汊道口门地貌现代演变

沙扒及其上游儒洞湾是一个有一定规模,比较稳定的河口湾型潮汐汊道,在波浪与潮流共同作用并以潮流为主的动力条件下,口门地区发育有潮流深槽、涨槽三角洲、水道边缘坝、拦门沙浅滩、边缘涨潮水道及内弯沙嘴等地貌类型。近年来,各种人类活动引起水文泥沙条件变化,导致东槽萎缩、西槽复苏、南槽转向、拦门沙东移并靠岸、港南沙嘴变低内移等现代演变过程。在港口现划与整治时必须对此充分考虑。     

深圳湾的演变与开发利用

本文描述了深圳湾的历史发展过程。根据1907年和1949年历史海图对比,计算出42年来深圳湾的淤积强度,预估了深圳湾的冲淤变化。结果表明,深圳湾自形成以来一直处于缓慢的淤浅状态。最后讨论了有关深圳湾的开发利用问题。     

广东和海南岛砂质海岸地貌及其开发利用

砂质海岸是广东和海南岛主要岸线类型,占岸线总长1/3以上,其规模取决于岸线轮廓、物质来源、海岸动力等因素。据不同动力过程、粒度、结构与历史的差别,从海向陆一般可分为海滩沙、岸堤沙,风积沙和晚更新世老红砂等不同沉积类型;据形态特点、沉积特征和分布情况,可将现代砂质海岸分为7种地貌类型。砂质海岸蕴藏着可供开发利用的资源,如沙荒地的改造利用、砂矿开采、海滨旅游、港口建设等。     

Restoration of oiled mussel beds in Prince William Sound, Alaska

Natural loss of hydrocarbons was often low from mussel (Mytilus trossulus) beds (which were typically not cleaned after the Exxon Valdez oil spill), thus this habitat remained a long-term source of oil. Consequently, experimental restoration of nine contaminated beds was attempted in 1994; mussels were removed, contaminated surface sediment was replaced (33 metric tons), and original mussels were returned. Hydrocarbon concentrations and mussel populations were monitored for 5 years thereafter. Post-restoration mussel population fluctuations were indistinguishable from regional changes. Increased short-term oil loss was apparent, but long-term (5 year) improvement was equivocal and difficult to distinguish from natural losses. By 1999, oil concentrations in mussels were typically at baseline levels in restored and oiled reference beds; concentrations in replaced sediment were elevated in one third of restored beds, indicating recontamination from underlying or surrounding sediment. Our results suggest mussel relocation is feasible but suggest oil might more effectively be removed from sediment mechanically or chemically than manually.     

珠江口外陆架晚第四纪最低海面的发现

根据珠江口外陆架海洋地质调查获得的地质-地球物理调查及钻井资料,从沉积相、地貌、微体古生物,~(14)C测年等多方面研究,以充分的证据,阐明了该区末次冰期结束时为距今13700±600a.当时海面低于现今海面131m。     

Induction of DNA strand breaks in the mussel (Mytilus trossulus) and clam (Protothaca staminea) following chronic field exposure to polycyclic aromatic hydrocarbons from the Exxon Valdez spill

In 2002, 13 years after the Exxon Valdez spill, mussels and clams were examined for lingering oil exposure and damage. Known oil patches were sampled at four locations, and compared to nearby reference areas (same bay), and were also compared to "hot reference" sites to verify the methods used (Cordova harbor and fresh diesel spill at Port Chalmers). Passive samplers deployed for a month at the sites, along with tissue samples, confirmed that the oiled sites were oiled (fingerprinting back to Exxon Valdez oil) and that reference sites were clean. The highest PAH loads were detected in sub-surface interstitial waters at oiled sites. Exposure at the surface was generally low level, and probably intermittent. DNA damage was assessed in blood cells using sensitive comet analyses. DNA strand breakage was detected in both mussels and clams, with the highest level of damage detected at "hot reference" sites of Cordova harbor and Port Chalmers. Bioavailability and DNA damage at the oiled sties was low, indicating there has been substantial progress in recovery from the spill 13 years before, yet low level bioavailability and damage were still detectable.