Coastal environmental gradients – Key to reproduction habitat mapping of freshwater fish in the Baltic Sea

Habitat requirements of fish are most strict during the early life stages, and the quality and quantity of reproduction habitats lays the basis for fish production. A considerable number of fish species in the northern Baltic Sea reproduce in the shallow coastal areas, which are also the most heavily exploited parts of the brackish marine area. However, the coastal fish reproduction habitats in the northern Baltic Sea are poorly known. The studies presented in this thesis focused on the influence of environmental conditions on the distribution of coastal reproduction habitats of freshwater fish. They were conducted in vegetated littoral zone along an exposure and salinity gradient extending from the innermost bays to the outer archipelago on the south-western and southern coasts of Finland, in the northern Baltic Sea. Special emphasis was placed on reed-covered Phragmites australis shores, which form a dominant vegetation type in several coastal archipelago areas. The main aims of this research were to (1) develop and test new survey and mapping methods, (2) investigate the environmental requirements that govern the reproduction of freshwater fish in the coastal area and (3) survey, map and model the distribution of the reproduction habitats of pike (Esox lucius) and roach (Rutilus rutilus). The white plate and scoop method with a standardized sampling time and effort was demonstrated to be a functional method for sampling the early life stages of fish in dense vegetation and shallow water. Reed-covered shores were shown to form especially important reproduction habitats for several freshwater fish species, such as pike, roach, other cyprinids and burbot, in the northern Baltic Sea. The reproduction habitats of pike were limited to sheltered reed- and moss-covered shores of the inner and middle archipelago, where suitable zooplankton prey were available and the influence of the open sea was low. The reproduction habitats of roach were even more limited and roach reproduction was successful only in the very sheltered reed-covered shores of the innermost bay areas, where salinity remained low (< 4‰) during the spawning season due to freshwater inflow. After identifying the critical factors restricting the reproduction of pike and roach, the spatial distribution of their reproduction habitats was successfully mapped and modelled along the environmental gradients using only a few environmental predictor variables. Reproduction habitat maps are a valuable tool promoting the sustainable use and management of exploited coastal areas and helping to maintain the sustainability of fish populations. However, the large environmental gradients and the extensiveness of the archipelago zone in the northern Baltic Sea demand an especially high spatial resolution of the coastal predictor variables. Therefore, the current lack of accurate large-scale, high-resolution spatial data gathered at exactly the right time is a considerable limitation for predictive modelling of shallow coastal waters.

Fish Habitat Utilization Patterns and Evaluation of the Efficacy of Marine Protected Areas in Hawaii: Integration of NOAA Digital Benthic Habitat Mapping and Coral Reef Ecological Studies

Over the past four decades, the state of Hawaii has developed a system of eleven Marine Life Conservation Districts (MLCDs) to conserve and replenish marine resources around the state. Initially established to provide opportunities for public interaction with the marine environment, these MLCDs vary in size, habitat quality, and management regimes, providing an excellent opportunity to test hypotheses concerning marine protected area (MPA) design and function using multiple discreet sampling units. NOAA/NOS/NCCOS/Center for Coastal Monitoring and Assessment’s Biogeography Team developed digital benthic habitat maps for all MLCD and adjacent habitats. These maps were used to evaluate the efficacy of existing MLCDs for biodiversity conservation and fisheries replenishment, using a spatially explicit stratified random sampling design. Coupling the distribution of habitats and species habitat affinities using GIS technology elucidates species habitat utilization patterns at scales that are commensurate with ecosystem processes and is useful in defining essential fish habitat and biologically relevant boundaries for MPAs. Analysis of benthic cover validated the a priori classification of habitat types and provided justification for using these habitat strata to conduct stratified random sampling and analyses of fish habitat utilization patterns. Results showed that the abundance and distribution of species and assemblages exhibited strong correlations with habitat types. Fish assemblages in the colonized and uncolonized hardbottom habitats were found to be most similar among all of the habitat types. Much of the macroalgae habitat sampled was macroalgae growing on hard substrate, and as a result showed similarities with the other hardbottom assemblages. The fish assemblages in the sand habitats were highly variable but distinct from the other habitat types. Management regime also played an important role in the abundance and distribution of fish assemblages. MLCDs had higher values for most fish assemblage characteristics (e.g. biomass, size, diversity) compared with adjacent fished areas and Fisheries Management Areas (FMAs) across all habitat types. In addition, apex predators and other targeted resources species were more abundant and larger in the MLCDs, illustrating the effectiveness of these closures in conserving fish populations. Habitat complexity, quality, size and level of protection from fishing were important determinates of MLCD effectiveness with respect to their associated fish assemblages. (PDF contains 217 pages)

Mapping reef fish and the seascape: using acoustics and spatial modeling to guide coastal management

Reef fish distributions are patchy in time and space with some coral reef habitats supporting higher densities (i.e., aggregations) of fish than others. Identifying and quantifying fish aggregations (particularly during spawning events) are often top priorities for coastal managers. However, the rapid mapping of these aggregations using conventional survey methods (e.g., non-technical SCUBA diving and remotely operated cameras) are limited by depth, visibility and time. Acoustic sensors (i.e., splitbeam and multibeam echosounders) are not constrained by these same limitations, and were used to concurrently map and quantify the location, density and size of reef fish along with seafloor structure in two, separate locations in the U.S. Virgin Islands. Reef fish aggregations were documented along the shelf edge, an ecologically important ecotone in the region. Fish were grouped into three classes according to body size, and relationships with the benthic seascape were modeled in one area using Boosted Regression Trees. These models were validated in a second area to test their predictive performance in locations where fish have not been mapped. Models predicting the density of large fish (≥29 cm) performed well (i.e., AUC = 0.77). Water depth and standard deviation of depth were the most influential predictors at two spatial scales (100 and 300 m). Models of small (≤11 cm) and medium (12–28 cm) fish performed poorly (i.e., AUC = 0.49 to 0.68) due to the high prevalence (45–79%) of smaller fish in both locations, and the unequal prevalence of smaller fish in the training and validation areas. Integrating acoustic sensors with spatial modeling offers a new and reliable approach to rapidly identify fish aggregations and to predict the density large fish in un-surveyed locations. This integrative approach will help coastal managers to prioritize sites, and focus their limited resources on areas that may be of higher conservation value.

Analyzing and mapping fish assemblages off central California, USA

This study describes fish assemblages and their spatial patterns off the coast of California from Point Arena to Point Sal, by combining the results of the multivariate analyses of several fisheries datasets with a geographic information system. In order to provide comprehensive spatial coverage for the areas of inshore, continental shelf, and continental slope, three fisheries datasets were analyzed: 1) Inshore: the California Department of Fish and Game dataset of fishery-dependent commercial passenger fishing vessel trips that targeted rockfish; 2) Continental Shelf: the National Marine Fisheries Service (NMFS) fishery-independent bottom trawls; and 3) Continental Slope: the NMFS fishery-independent bottom trawls on the continental slope. One-hundred seven species were analyzed. These species represented those captured in at least 5% of the fishing trips or trawls in at least one of the three data sets. We analyzed each of the three datasets separately, and the three sets of results were combined to define 28 species assemblages and 23 site groups. A species assemblage consisted of species caught together, whereas a site group consisted of fishing trips or trawl locations that tended to have the same species assemblages. At the scale of these datasets, 97% of all site groups were significantly segregated by depth.

Mapping of the Indian fisheries growth rate and fish consumption through GIS

In the present study, Indian fisheries growth rate and fish consumption have been analyzed through GIS mapping. The analyses were based on the state-level fisheries data of India collected from the secondary sources. Accordingly, the paper contains one thematic map containing two layers. To achieve this, all the data have been brought into a tabular form through Microsoft Excel and then joined to Map Info Professional Version 8.0 GIS software with digitized map of India for further analysis to generate thematic maps. In this thematic map, the first Jayer represents the growth-rate of fish production for the period 1990-2004 and the second layer represents fish consumption for the year 2003. The thematic map represented in graphic form presents inland, marine and total growth rates, and also the rural and urban fish consumption at the state levels. This study will be useful to fish traders, planners, researchers and administrators in fisheries policy formulation for sustainable development.

Chromosome Mapping of Retrotransposable Elements Rex1 and Rex3 in Three Fish Species in the Subfamily Hypoptopomatinae (Teleostei, Siluriformes, Loricariidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

5S rDNA chromosomal mapping and COI sequence analysis reveal differentiation among distinct populations of a characid fish Serrapinnus notomelas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Chromosome Evolution in African Cichlid Fish: Contributions from the Physical Mapping of Repeated DNAs

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Chromosomal Variability among Allopatric Populations of Erythrinidae Fish Hoplias malabaricus: Mapping of Three Classes of Repetitive DNAs

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Cytogenetic Mapping of the Retroelements Rex1, Rex3 and Rex6 among Cichlid Fish: New Insights on the Chromosomal Distribution of Transposable Elements

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Comparative chromosome mapping of repetitive sequences. Implications for genomic evolution in the fish, Hoplias malabaricus

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Genomic organization and comparative chromosome mapping of the U1 snRNA gene in cichlid fish, with an emphasis in Oreochromis niloticus

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)