ISSN:0035-919X    

DOI:10.1080/00359196909519086

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

A bathymetric survey has been carried out of lakes Sibayi, Nhlange and Sifungwe in Zululand. The lakes appear to have originated as estuaries which were later drowned either through eustatic rise in sea-level or isostatic drowning of the shoreline. Morphometric measurements show that Lake Sibayi is the largest lake having the largest surface area, greatest maximum and mean depth and containing the largest volume of water. The level of Lake Sibayi apparently fluctuates considerably. Lakes Nhlange and Sifungwe are normally connected to the sea and their levels do not fluctuate.

ISSN:0035-919X    

DOI:10.1080/00359196909519087

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

ISSN:0035-919X    

DOI:10.1080/00359196909519088

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

A preliminary investigation of the submerged macrophytes and fish of Lake Sibayi was carried out using diving techniques. In the main basin of the lake, macrophytes were absent from water shallower than 1 · 5 to 2 metres, apparently due to wave action. Down to a depth of 5 metres,Potamogeton pectinatusL. andP. schweinfurthiiA. Benn were the dominant species. Below 5 metresMyriophyllum spicatumL. was dominant. Macrophytes were absent from water deeper than 7 metres, probably due to reduced light intensities.

ISSN:0035-919X    

DOI:10.1080/00359196909519089

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

The bottom substrates of the freshwater Lake Sibayi are mainly fine sands. Silt substrates occur mainly in the valleys leading from the western and northern arms of the lake underwater in the main basin of the lake.

ISSN:0035-919X    

DOI:10.1080/00359196909519090

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

The marine and estuarine crabHymenosoma orbicularehas been found living in fresh water in Lake Sibayi. Experiments have been carried out to determine whetherH. orbicularenormally exposed to sea water can live and breed in low dilutions of sea water. The zoeae are the most sensitive stage but they possess a marked acclimation ability. Preliminary experiments indicate thatH. orbicularefrom subtropical waters have a much higher upper lethal temperature than crabs from warm temperate regions. The size ofH. orbiculareis not salinity dependent, as was previously thought. It appears thatH. orbiculareliving in Lake Sibayi do not constitute a distinct physiological race.

ISSN:0035-919X    

DOI:10.1080/00359196909519091

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

A mass mortality of mangroves occurred in the Kosi estuary in 1965. Events leading up to the mortality were investigated and it was concluded that flooding of the estuary following upon closure of the mouth for five months was responsible. The existing distribution of mangroves, both dead and alive, was recorded and the percentage survival of the various species was determined by means of counts. It was found that mangroves on high ground, chieflyLumnitzera racemosaWilld., had survived. It appeared thatBruguiera gymnorrhiza(L.) Lam. would probably become the dominant mangrove in the intertidal zone in the future, althoughAvicennia marina(Forsk.) Vierh. andRhizophora mucronataLam. would not disappear from the estuary.

ISSN:0035-919X    

DOI:10.1080/00359196909519092

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

ISSN:0035-919X    

DOI:10.1080/00359196909519093

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor