published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

The illegal sale of East Coast rock lobster (Panulirus homarus) along the N2 highway at Mfazazana on the south coast of KwaZulu-Natal, continues to create tension between the local community and conservation and other authority structures in the region. Panulirus homarus (P. homarus) is a valuable commodity in an area distant from industry and other economic prospects and is within easy reach of both the harvester, in terms of its intertidal living space and the market, in terms of the N2 and the economy in seafood prevalent in the region. P. homarus is therefore at risk by virtue of its biology and habitat, and the illegal nature of its capture tests the parameters of sustainable resource management still further. This research addresses the issue of sustainable resource use through an examination of the perceptions of the various stakeholders who are involved in the use and protection of P. homarus at Mfazazana. This study was commissioned by the Communications Section of the KwaZulu Department of Nature Conservation (KONC) in response to continued illegal harvesting and trade of P. homarus at Mfazazana. One of the mandates of the Communications Section is to initiate and maintain environmental education programmes and thus comply with the KONC mission statement (See Appendix 1a). Specific objectives of the study include: • how respondents perceive their relationship with, responsibility to and role in terms of P. homarus • how respondents perceive their relationship with, responsibility to and role in terms of the others involved with P. homarus • how present legislation is perceived by stakeholders • what options exist regarding the regulation and/or management of P. homarus • whether changes over time have occurred in the respondents' relationship with P. homarus Fishing and trading activities were inv~stigated using informal, loosely structured questionnaires which elicited qualitative information. Two main groups were selected. and respondents were interviewed either individually or in small groups. The crayfishers made up the first group and the resource managers made up the second group which included the Natal Parks Board (NPB), the KONG, the Hibberdene Tourism and Publicity Association, the Community Policing Forum, the Community Development Forum at Mfazazana and the South Coast Fishing Forum. The study provided an understanding and explanatiol] of how the elements of the locality interact with underlying structures and human agency in time to produce the conflict over the marine resource P. homarus at Mfazazana. It was found that the conflict between stakeholders, as a result of differing perceptions regarding the illegal harvesting of the resource, was obstructing the sustainable management of P. homarus at Mfazazana. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1997

This research study is divided into 4 major sections. Section A deals with the world-wide distribution of the haematoprotozoan parasites of marine fishes. These are tentatively divided into 3 major groups: the Haemogregarines, the Trypanosomes and the Trypanoplasms and one group of ill defined and controversal organisms including Haemohormidium sp. and Dactylosoma sp. The results of extensive surveys of the coastal waters of France, Scotland and Wales with added examples from the Mediterranean Sea substantiate the zoogeographical distribution of these parasites. Two species of haematoprotozoan parasites Haemogregarina simondi and Trypanosoma soleae are re-described, earlier accounts dating from the beginning of the century being considered incomplete. A new species of haemogregarine is described from the farmed turbot (Scophthalmus maximus) as Haemogregarina sachai n. sp. and an unidentified species of Haemohormidium found occasionally in turbot and Dover sole (Solea soles) is also described. In addition Haemogregarina sp. were encountered in certain wild marine fish from the Atlantic coast of France e. g. Zeus faber, Sebastes sp., Trisopterus luscus, Pagellus bogaraveo and Raja sp. and from the coastal waters of Malta e. g. Peristedion cataphractum and Oblade melanura. However, they were not found in sufficient numbers to allow a definite description. The value of surveys of wild fish populations is discussed in the light of zoogeographical distribution, the apparent periodicity of these parasites and a seasonal variation of parasitism. Section B attempts to summarize the knowledge of the mode of transmission of marine haematoprotozoan parasites by piscicolid leeches as intermediate hosts and vectors. The developmental stages of a trypanosome, probably Trypanosoma murmanensis from the Atlantic cod Gadus morhua are described in the marine leech Calliobdella nodulifera. Stages of a haemogregaririe were observed in the same leech. The development of the turbot haemogregarine Haemogregarina sachai n. sp. in artificially infected leeches is also described up to the 20th day post infection. Transmission of this haemogregarine to apparently uninfected turbot via this leech was not successful. Various stages of development of Haemogregarina simondi are described in its apparently natural vector, the marine leech Hemibdella soleae, and transmission with infected leeches to apparently healthy hatchery reared soles was achieved. Thus it was shown for the first time that marine leeches can serve also as vectors for haemogregarines. Stages of this haemogregarine are also described in the blood-sucking ectoparasitic copepod Lernaeocera sp. parasitizing the haemogregarine infected soles. These results are discussed in relation to the feeding behaviour and migration patterns of the fish hosts, the periodicity of the parasites and possible other vectors or other ways of acquiring an infection with these haematoprotozoan parasites. In Section C the pathogenicity of the haematoprotozoan parasites of marine fishes is summarized from previous accounts among wild fish populations and compared with the situation in aquaculture. The pathogenicity of the two haemogregarines, Haemogregarina simondi and Haemogregarina sachai n. sp., accidentally introduced into several fish farming establishments connected with the effluent cooling waters of a nuclear power station is described with special reference to the possible source of the infection. The results of therapy trials and control programs are discussed in the light of the periodic reappearance of the parasites, the possibility of carrier fish existing, the immune status of the host and the possible role of an intermediate host or vector in maintaining the infection. Possible means of controlling the pathogenicity of marine haemogregarines and perhaps other haematoprotozoan parasites when they occur in farmed marine fishes are also discussed. In Section D are described for the first time, the ultrastructural characteristics of various stages of the haematoprotozoan parasites of marine fishes in fish hosts and vectors. The electronmicroscopical studies are limited to Haemogregarina sachai n. sp. and Haemogregarina simondi, for which the ultrastructure of schizonts from the spleen and blood, intracellular merozoites and free gametocytes were contrasted. In addition stages of H. simondi were demonstrated in Hemibdella soleae and Lernaeocera sp. The fine structure of the various organelles encountered was compared with that of related organisms from other cold-and warm-blooded vertebrates. In conclusion attention is drawn to the need for more investigations in this field of host-parasite relationship of marine haematoprotozoan parasites and their vectors and their pathogenic-action as seen in a confined and artificial environment such as the marine aquaculture.

Thesis (M.Sc. (Ichthyology & Fisheries Science)) - Rhodes University, 2008.

Th.--Sci. nat.--Paris 6, 1978.

Thesis (M.Sc. (Ichthyology & Fisheries Science)) - Rhodes University, 2009.

The gammarid amphipod Eogammarus confervicolus (Stimpson) was investigated as a potential mass culture organism, with utility as a diet supplement for artificially reared fish. Suitable conditions for large-scale culture were determined in a series of experiments. E. confervicolus demonstrated wide salinity and temperature tolerances, with best survival at low salinities (5 - 10⁰/00) and temperatures (5⁰ - 10⁰C). Population densities greater than 2 mg/1 reduced amphipod growth and survival, although densities may be increased with a flow-through system. E. confervicolus showed good growth and survival on a variety of algae and associated epiphytes, demonstrating the broad diet of the species. Clumping diatoms or phytodetritus were suggested as suitable foods for mass culture. Maintenance of populations over three generations showed the feasibility of long term culture of this amphipod. Short term growth rates of juvenile coho at 12°C were similar on live amphipods (3.2%/day), freeze-dried amphipods (2.4%/day) and Oregon Moist Pellets (3.1%/day). Protein analysis showed E. confervicolus to have a well-balanced amino acid spectrum, and proximate analysis indicated that the amphipod was a nutritionally satisfactory component of fish diets. A Leslie matrix model was developed from information about growth, mortality and fecundity of Eogammarus confervicolus under optimal conditions, and was used to test various harvest strategies. Highest yield of the strategies examined was produced by a weekly 41% harvest applied to amphipods between 0.6 and 2.2 mg dry weight. Further experiments testing the predictions of the Leslie matrix model were recommended. / Science, Faculty of / Zoology, Department of / Graduate

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

Kappaphycus alvarezii (Doty) Doty ex P. C. Silva é uma alga vermelha comercialmente importante por ser a principal fonte de carragenana kappa, hidrocolóide utilizado como agente espessante e estabilizante em alimentos, fármacos e cosméticos. Devido à sua importância, é fundamental desenvolver bases tecnológicas visando sua maricultura sustentada e a seleção de linhagens mais produtivas com carragenanas de melhor qualidade. Esse trabalho teve como objetivos: 1. desenvolver a cultura de tecidos para a propagação de plantas matrizes, selecionar as melhores linhagens para cultivo in vitro e produzir novas linhagens; 2. testar a espécie como biofiltro em cultivos integrados com peixes e 3. analisar os efeitos de diferentes condições de cultivo no rendimento e na qualidade das carragenanas, segundo parâmetros comerciais. Para o primeiro objetivo, foram testadas cinco linhagens (tetrasporófitos marrom, verde e vermelho, gametófito feminino e linhagem “Edison de Paula", EP, selecionada a partir da germinação de tetrásporos) para definir o sistema experimental mais adequado para a micropropagação. Explantes da linhagem EP foram tratados com colchicina com a finalidade de induzir linhagens poliplóides. Essa linhagem foi selecionada por apresentar maior tolerância aos procedimentos de esterilização utilizados na cultura de tecidos. Apesar das altas taxas de indução de calos observadas em todas as linhagens, a regeneração de talos a partir dos calos (regeneração indireta) foi difícil. A regeneração de talos a partir dos explantes (regeneração direta) foi estimulada pela utilização de fitorreguladores e da colchicina. A contaminação dos cultivos por uma espécie filamentosa Acrochaetium no talo da linhagem EP foi inibida com a adição de 90 mM de glicerol. A formação de novas linhagens poliplóides através da utilização de colchicina não foi demonstrada. Os resultados indicaram que é possível utilizar a micropropagação através da produção de explantes para manutenção de um estoque de plantas matrizes de diferentes linhagens em laboratório. Para o segundo objetivo, o tetrasporófito marrom da espécie foi cultivado em tanques com água do mar e com efluente da criação de peixes da espécie Trachinotus carolinus (pampos) por 10 dias. As taxas de crescimento das algas cultivadas nos tanques foram mais baixas que às obtidas em cultivo no mar. Os valores máximos da taxa de remoção nos efluentes foram: NO3- = 18,2%; NO2- = 50,8%; NH4+ = 70,5% e PO43- =26,8%, nas condições testadas. Todas as plantas sobreviveram até o final do período experimental, mas apresentaram sinais de "ice-ice", doença associada ao estresse fisiológico. Diferenças entre os rendimentos de carragenana de algas cultivadas em água do mar ou em efluente de criação de peixes não foram significativas. Esses resultados demonstraram que é possível utilizar K. alvarezii como biofiltro de águas eutrofizadas derivadas da criação de peixes embora a espécie seja típica de águas oligotróficas. Para o terceiro objetivo, o gametófito feminino foi cultivado em balsas flutuantes segundo diferentes condições de cultivo (período de cultivo, profundidade e densidade do plantio). As carragenanas das plantas cultivadas nesses tratamentos foram extraídas e algumas propriedades foram determinadas. As taxas de crescimento variaram de 5,2 a 7,2% dia-1, com as maiores taxas obtidas em 28 dias de cultivo, em profundidade de 0 e 0,5 m e densidade do plantio de 12 e 8,4 plantas m-2. As condições de cultivo que forneceram melhor carragenana, segundo padrões comerciais foram: 45 dias de cultivo, na superfície, com densidade de 12 plantas m-2. Considerando que esse cultivo foi realizado na estação menos favorável do ano (inverno) para o crescimento das plantas, esses resultados indicam que o local onde a espécie foi introduzida é adequado para a implementação do cultivo comercial. Através dos resultados obtidos nesse trabalho, desejamos contribuir com a maricultura sustentável de uma espécie promissora no Brasil, com excelente potencial econômico reconhecido mundialmente, além de deixar algumas sugestões e propostas para novos estudos. / Kappaphycus alvarezii (Doty) Doty ex P. C. Silva is a red seaweed commercially important for being the main source of kappa carrageenan, hydrocolloid utilised as thickener and stabiliser in foods, medicaments and cosmetics. Due to its importance it is fundamental to develop technological bases on purpose of its sustainable mariculture and the selection of more productive strains with best qualities carrageenans. The objectives of this work were: 1. to develop the tissue culture for micropropagation of matrix plants, to select the better strains for in vitro culture and to produce new strains; 2. to test the species as biofilter in integrated cultivation with fishes and 3. to analyse the effects of different cultivation conditions in carrageenan yield and quality, according to commercial parameters. For the first objective, five strains (brown, green and red tetrasporophytes, female gametophyte and "Edison de Paula" strain, EP, selected from tetraspores progeny) were tested to define the experimental system suitable for micropropagation. Explants from EP strain were treated with colchicine with the aim of induce polyploid strains. This strain was selected by presenting high tolerance to sterilization procedures used in tissue culture. Despite the high rates of callus induction observed in all strains, thallus regeneration from callus (indirect regeneration) was difficult. Thallus regeneration from explants (direct regeneration) was stimulated by phytorregulators and colchicine. The culture contamination by a filamentous species Acrochaetium in the tallus of EP strain was inhibited with addition of 90 mM glycerol. The formation of polyploid strains by colchicine treatments was not proved. The results indicated that it is possible to use the micropropagation through the production of explants for maintaining matrix plants stocks from different strains in laboratory. For the second objective, the brown tetrasporophyte was cultivated in tanks with seawater and with effluents of the fish Trachinotus carolinus (pampos) rearing for 10 days. Growth rates of seaweeds cultivated in tanks was lower than those cultivated in the sea. The maximum values of removal rates from the effluents were: NO3- = 18.2%; NO2- = 50.8%; NH4+ = 70.5% and PO43- =26.8% in the conditions tested. All plants survived until the end of experimental period, but they presented signals of "ice-ice", disease associated to physiological stress. Differences between the carrageenan yields from plants cultivated in seawater and in effluents of fish rearing were not significant. These results showed that it was possible utilised the seaweed K. alvarezii as biofilter in effluents from fish rearing, although the species is typical of oligotrophic waters. For the third objective, the female gametophyte was cultivated from floating raft according to different cultivation conditions (i.e. cultivation period, depth and planting density). Carrageenan from the plants cultivated under these treatments was extracted and some properties were determined. Growth rates ranged from 5.2 to 7.2% day-1, with the higher rates obtained in 28 day cultivation period, at 0 and 0.5 m of depth and planting density of 12 and 8.4 plants m-2. The cultivation conditions that supplied the best carrageenan, according to commercial patterns were: 45 days of cultivation, in surface, with planting density of 12 plants m-2. Considering that this cultivation was conducted in the unfavourable season of the year (winter) for the growth of K. alvarezii, the results indicated that the site where the species was introduced is adequate to the implementation of commercial cultivation. Through the results obtained in this work, we wish to contribute with sustainable mariculture of a successful species in Brazil, with excellent economic potential recognised in all world, besides leave some suggestions and proposes for new studies.

No description available.