This dissertation analyses the effects of current fisheries practices and management regulations of the green spiny lobster (Panulirus gracilis) in the Eastern Tropical Pacific Region (ETP). P. gracilis has reached a critical state in the ETP. Country-based studies report that between 60 and 98% of lobsters caught in the wild are under the minimum landing size (MLS). This means that spiny lobsters are being extracted before reproducing and contributing to the replenishment of interconnected populations. The recovery of green spiny lobster populations in the ETP and the future maintenance of a sustainable fishery will depend on effective management decisions and on taking in account environmental factors that influence the population dynamics of the lobsters. In the first study (Chapter 2), the B52 Spiny Lobster individual based simulation model was used for conducting a population viability analysis to quantify the effect of current fishing practices and the effect of varying management regulations on minimum landing size (MLS) and fishing effort. The best suit of regulations to maintain the highest abundance, production of offspring and catch is to protect juveniles and egged females, and to establish a MLS that assures the reproduction of individuals before being extracted. This study revealed regional variations, however the patterns and the causes for variation were not yet clear. This led to the next chapters in this dissertation. In Chapter 3, I used a meta-analysis to explore regional lobster variability by comparing published studies from the ETP. The objective was to identify patterns of variation related to geographic and environmental factors of the region that can inform the establishment and evaluation of coordinated regulations. Morphological relationships showed to be more variable at northern latitudes, where the mean annual sea surface temperatures are higher than at lower temperatures at the Equator. In terms of management, MLS regulations should be adapted accounting for the effect of sea surface temperature and its variation. Additionally, it was observed that monitoring methodologies are not standardized within the region and even in some cases, neither within countries. Furthermore, in most places monitoring of the spiny lobster fishery happens sporadically, only in Galapagos takes place every year. Identifying patterns of variations can improve the accuracy of prediction models which can help to explore, design, and apply more effective management measures, as well as promote regional coordination to support the recovery and maintenance of spiny lobsters. In Chapter 4, I contrast current Ecuadorian minimum landing size (MLS) regulation to lobster empirical measurements within Ecuador in order to recognize potential pitfalls for management enforcement. I used linear regression and multiple regression models with the objective of identifying potential relative size variations of the individuals caught in the wild over time and in the different fishing areas in Ecuador, as well as to analyse the effect of locality, sex, age and mean SST on the tail length/total length ratio. Morphological relations were significantly different among sexes, in time and by all sites. Most importantly, this study shows that current minimum size regulations are not applicable to all sites. Additionally, I found that water temperature has a significant effect on morphological relationship variations. However, it was not the main site-specific variable responsible for explaining such variations. In general, this work emphasizes the need for length data collection standardization and the consideration of temporal and spatial variation implications in national and regional fishery management planning, enforcement and evaluation.

Diploma thesis analyzes the viability of the selected species populations in the Czech Republic. The thesis is divided into two main parts. The first part contains a stochastic model simulating possible scenarios of the Eurasian lynx population size in the Czech Republic. For this model program Vortex was used. The second part is focused on Time series analysis of the Grey Partridge and the Common Kingfisher population, where data was obtained from the Czech Society for Ornithology. This analysis aims on identification of factors that may affect the viability of the two bird species.

With a declining population of roughly 3000-5000 individuals in Africa, African wild dogs (Lycaon pictus) are one of the most endangered carnivores in the world. As the global human population expands, it is becoming increasingly unlikely that large portions of land will be set aside for conservation, especially in developing countries. Thus, recent wild dog conservation efforts in South Africa have concentrated on establishing a managed metapopulation. A metapopulation is a group of geographically isolated subpopulations of a species that are managed (using supplementation and harvesting) to mimic natural gene flow. The Great Fish River Nature Reserve (GFRNR) in the Eastern Cape Province of South Africa has been identified as a potential reserve to become part of the national wild dog metapopulation. My research aimed to conduct a feasibility assessment of the long-term (~ 25 years) success of a wild dog reintroduction into the GFRNR. This assessment included biological modelling of wild dogs and their expected prey, and determining the potential anthropogenic threats to wild dogs on the private and communal land surrounding the reserve. I used VORTEX population modelling and determined that the GFRNR is likely to have a wild dog carrying capacity of ~22 individuals. Using a 25-year modelling simulation, the most appropriate wild dog reintroduction scenario would be to reintroduce six females and four males initially and supplement the population with one female and two males in years 3, 10, 15 and 23. In addition, the harvesting/removal of one male and one female in years 10 and 20 would be required to ensure 100% population persistence and adequate genetic diversity. Kudu (Tragelaphus strepsiceros) and bushbuck (Tragelaphus scriptus) are expected to be the two most important prey species for reintroduced wild dogs in the GFRNR. Furthermore, wild dogs are likely to prefer the north-western and south-western sectors of the reserve because of the relatively high prey densities in these areas. However, regular monitoring of both the potential prey and the wild dog populations is essential to ensure persistence of the wild dogs and to prevent prey populations decreasing precipitously. Using structured questionnaire interviews (n = 128), I found that while neighbouring land owners and local communities were generally positive about the potential wild dog reintroduction (56 % of all respondents), several threats to wild dogs were identified along the reserve boundary and on the adjoining unprotected land. Some private landowners and members of rural communities around the reserve (34 %) stated that they would kill any wild dogs that dispersed onto their land. In addition, some respondents (8 %) admitted to believing in traditional uses for wild dog products (e.g. fur) which could result in the illegal killing of wild dogs outside of the GFRNR for traditional purposes. Poaching and the presence of unvaccinated domestic dogs on neighbouring land were also identified as being potential threats to a reintroduced wild dog population. However, such anthropogenic threats appear to be localised to the western and southern boundaries of the reserve. Therefore, by implementing preventative measures (such as anti-snare collars, anti-poaching patrols and vaccination against rabies and canine distemper) the likelihood of such threats occurring can be reduced. I conclude that the GFRNR can sustain a population of wild dogs and successfully contribute to South Africa‘s national metapopulation. An additional reserve will benefit the country‘s metapopulation by increasing the number of wild dogs available for translocation, thereby increasing genetic diversity and overall resilience (to environmental change, disease etc.) of South Africa‘s wild dog population. This will contribute towards the future conservation of this endangered species.

This dissertation analyses the effects of current fisheries practices and management regulations of the green spiny lobster (Panulirus gracilis) in the Eastern Tropical Pacific Region (ETP). P. gracilis has reached a critical state in the ETP. Country-based studies report that between 60 and 98% of lobsters caught in the wild are under the minimum landing size (MLS). This means that spiny lobsters are being extracted before reproducing and contributing to the replenishment of interconnected populations. The recovery of green spiny lobster populations in the ETP and the future maintenance of a sustainable fishery will depend on effective management decisions and on taking in account environmental factors that influence the population dynamics of the lobsters. In the first study (Chapter 2), the B52 Spiny Lobster individual based simulation model was used for conducting a population viability analysis to quantify the effect of current fishing practices and the effect of varying management regulations on minimum landing size (MLS) and fishing effort. The best suit of regulations to maintain the highest abundance, production of offspring and catch is to protect juveniles and egged females, and to establish a MLS that assures the reproduction of individuals before being extracted. This study revealed regional variations, however the patterns and the causes for variation were not yet clear. This led to the next chapters in this dissertation. In Chapter 3, I used a meta-analysis to explore regional lobster variability by comparing published studies from the ETP. The objective was to identify patterns of variation related to geographic and environmental factors of the region that can inform the establishment and evaluation of coordinated regulations. Morphological relationships showed to be more variable at northern latitudes, where the mean annual sea surface temperatures are higher than at lower temperatures at the Equator. In terms of management, MLS regulations should be adapted accounting for the effect of sea surface temperature and its variation. Additionally, it was observed that monitoring methodologies are not standardized within the region and even in some cases, neither within countries. Furthermore, in most places monitoring of the spiny lobster fishery happens sporadically, only in Galapagos takes place every year. Identifying patterns of variations can improve the accuracy of prediction models which can help to explore, design, and apply more effective management measures, as well as promote regional coordination to support the recovery and maintenance of spiny lobsters. In Chapter 4, I contrast current Ecuadorian minimum landing size (MLS) regulation to lobster empirical measurements within Ecuador in order to recognize potential pitfalls for management enforcement. I used linear regression and multiple regression models with the objective of identifying potential relative size variations of the individuals caught in the wild over time and in the different fishing areas in Ecuador, as well as to analyse the effect of locality, sex, age and mean SST on the tail length/total length ratio. Morphological relations were significantly different among sexes, in time and by all sites. Most importantly, this study shows that current minimum size regulations are not applicable to all sites. Additionally, I found that water temperature has a significant effect on morphological relationship variations. However, it was not the main site-specific variable responsible for explaining such variations. In general, this work emphasizes the need for length data collection standardization and the consideration of temporal and spatial variation implications in national and regional fishery management planning, enforcement and evaluation.

No description available.

No description available.

Assessment of trophic interactions between increasing populations of New Zealand fur seals (Arctocephalus forsteri) and fisheries in southern Australia is limited due to a lack of species specific demographic data and an understanding of the factors influencing population growth. To establish species specific demographic parameters a cross-sectional sample of New Zealand fur seal females (330) and males (100) were caught and individually-marked on Kangaroo Island, South Australia between 2000 and 2003. The seals were aged through examination of a postcanine tooth, which was removed from each animal to investigate age-specific life-history parameters. Annual formation of cementum layers was confirmed and accuracy in age estimation was determined by examination of teeth removed from individuals of known-age. Indirect methods of assessing reproductive maturity based on mammary teat characteristics indicated that females first gave birth between 4-8 years of age, with an average age at reproductive maturity of 5 years. Among reproductively mature females, age-specific reproductive rates increased rapidly between 4-7 years of age, reaching maximum rates of 70-81% between 8-13 years, and gradually decreased in older females. No females older than 22 years were recorded to pup. Age of first territory tenure in males ranged from 8-10 years. The oldest female and male were 25 and 19 years old, respectively. Post-weaning growth in females was monophasic, characterised by high growth rates in length and mass during the juvenile growth stage, followed by a gradual decline in growth rates after reproductive maturity. In contrast, growth in males was biphasic and displayed a secondary growth spurt in both length and mass, which coincided with sexual and social maturation, followed by a rapid decline in growth rates. Age-specific survival rates were high (0.823-0.953) among prime-age females (8-13 yrs of age) and declined in older females. Relative change in annual pup production was strongly correlated with reproductive rates of prime-age females and adult female survival between breeding seasons.

The project was initiated by Eastern Cape Parks (ECP) as a request for the construction of inventories of priority species and their population levels inside three nature reserves on the Eastern Cape Wild Coast, South Africa, and to develop a strategic management plan to manage these natural resources in each reserve. Thirty key species were identified by local communities in and around Dwesa-Cwebe, Silaka and Mkambati Nature Reserves through community workshops. For forested areas belt transects of 100 m x 6 m where used. The basal circumference of key tree species within the belt transect was measured as well as the height of saplings (height < 150 m). Tree species were categorized based on densities, size class distribution (SCD) curves and values, and spatial grain. For grassland areas straight transects of 200 m long were used, along which ten 3 m x 3 m quadrates were placed at 20 m intervals. Within each grassland transect the height of herbs or tuft diameter of grasses was recorded and percentage cover estimated. Grassland species were categorized based on density, SCD curves and percentage cover. All species were placed into harvesting categories based on analysed ecological data that was collected in the field. Category 1 species were very rare or not found in the reserve and it was recommended that species be conserved and monitored. Category 2 species had low densities in the reserve indicating declining populations and was suggested that these be monitored and not harvested. Category 3 species had high densities and have potential for harvesting with strict limitations. Category 4 species were most abundant with very high densities and can be harvested within management guidelines. These categories were grouped further using social and ecological data such as harvesting risk, frequency of collection, use value and number of uses. This highlighted which species have conservation priority within each category and a decision can be made as to how intense or limited extraction should be. By incorporating GIS the distribution of each species was looked at and harvesting and non-harvesting zones established to determine where species can be extracted. Monitoring plans must consider the quantity of plant material collected, fire regimes, optimal harvesting rates and harvesting zones, and be able to pick up changes in populations. Also, it is important that the community be involved in conserving and monitoring these species. Adaptive monitoring and management must be used to steer harvesting practices in the Wild Coast reserves. This allows for the development of harvesting practices through ‘learning by doing’, and the evolution of good questions to guide monitoring decisions