Tropical seaweed beds as important habitats for juvenile fish

2017 ◽  
Vol 68 (10) ◽  
pp. 1921 ◽  
Author(s):  
S. A. Tano ◽  
M. Eggertsen ◽  
S. A. Wikström ◽  
C. Berkström ◽  
A. S. Buriyo ◽  
...  
Keyword(s):  
Fish Species ◽  
Fish Assemblages ◽  
Fish Habitat ◽  
Juvenile Fish ◽  
Visual Census ◽  
Seagrass Meadows ◽  
Commercially Important ◽  
Fish Habitats ◽  
Habitat Variables

Seaweed beds within tropical seascapes have received little attention as potential fish habitat, despite other vegetated habitats, such as seagrass meadows and mangroves, commonly being recognised as important nurseries for numerous fish species. In addition, studies of vegetated habitats rarely investigate fish assemblages across different macrophyte communities. Therefore, the aim of the present study was to investigate the role of tropical seaweed beds as fish habitat, particularly for juvenile fish, by comparing their fish assemblages with those of closely situated seagrass beds. Fish assemblages were assessed by visual census in belt transects, where fish were identified and their length estimated, and habitat variables were estimated for each transect. The abundance of juvenile fish in seaweed beds was twice as high as that in seagrass meadows, whereas there was no difference in total, subadult or adult fish abundance. In addition, the abundance of commercially important and coral reef-associated juveniles was higher in seaweed beds, as was fish species richness. Fish assemblages differed between habitats, with siganids being more common in seagrass meadows and juvenile Labridae and Serranidae more common in seaweed beds. These results highlight that tropical seaweed beds are important juvenile fish habitats and underscore the need to widen the view of the shallow tropical seascape.

Influence of habitat complexity on fish density and species richness in structurally simple forereef seagrass meadows

2018 ◽  
Vol 61 (6) ◽  
pp. 547-557 ◽  
Author(s):  
Nina Ann Jin Ho ◽  
Jillian Lean Sim Ooi ◽  
Yang Amri Affendi ◽  
Ving Ching Chong
Keyword(s):  
Species Richness ◽  
Habitat Complexity ◽  
Fish Assemblages ◽  
Fish Habitat ◽  
Relative Size ◽  
Shoot Density ◽  
Fish Density ◽  
Percent Cover ◽  
Seagrass Meadows ◽  
Fish Habitats

Abstract Seagrass meadows are highly productive habitats that support commercially and ecologically important fishes and invertebrates. However, evidence of fish-habitat relationships are seldom drawn from forereef seagrass meadows that are structurally simple in terms of species richness and relative size and, consequently, their role as habitats is unclear. In this study, fish-habitat relationships were examined in such meadows in the forereef seagrasses of Tinggi Island and Babi Besar Island, Malaysia, by documenting habitat complexity attributes (canopy height, shoot density and percent cover), distance to adjacent coral reefs, and water depth within 2×2 m quadrats. Fish assemblages were recorded using the Remote Underwater Video Station method. A total of 1166 individuals from 86 taxa were found and enumerated. This study showed that (1) fish density and species richness were significantly associated with seagrass percent cover alone; (2) commercially important carnivores formed the majority of the fish populations in the meadows, and (3) fish density and species richness were positively correlated with distance to the nearest adjacent coral reef, indicating the need to account for the effects of neighboring habitats in studies of this nature. Thus, structurally simple seagrass meadows are still important fish habitats, especially as feeding grounds for commercially significant carnivores.

scholarly journals Juvenile fish in Cystoseira forests: influence of habitat complexity and depth on fish behaviour and assemblage composition

2019 ◽  
Vol 20 (2) ◽  
Author(s):  
AMALIA CUADROS ◽  
JOAN MORANTA ◽  
LUIS CARDONA ◽  
PIERRE THIRIET ◽  
PATRICE FRANCOUR ◽  
...  
Keyword(s):  
Body Length ◽  
Fish Species ◽  
Habitat Complexity ◽  
Fish Assemblages ◽  
Juvenile Fish ◽  
The Body ◽  
Environmental Drivers ◽  
Independent Effect ◽  
Depth Range ◽  
Canopy Volume

The sublittoral forests formed by the fucoid algae Cystoseira spp. are important juvenile habitats for many Mediterranean fish species. However, the spatial variability of juvenile fish assemblages within the forests and the potential environmental drivers, such as depth and habitat complexity, remain poorly understood. We estimated densities, sizes and behaviours of juvenile fish assemblages in subtidal (0-15 meters) Cystoseira brachycarpa var. balearica forests in north Minorca Island (North-western Mediterranean Sea) over two consecutive autumns (2012 and 2013). Depth and forest complexity, here measured as canopy volume, had both a significant and independent effect on the juvenile fish assemblages in terms of species abundance composition and body size. Assemblages found in the shallowest depth range (3-4m) were characterized by greater densities of the ornate wrasse Thalassoma pavo, while those deeper (10-12m) had higher densities of the rainbow wrasse Coris julis, independently of its size composition. Juveniles of both species were more abundant in less complex forests; conversely juveniles of wrasses of the genus Symphodus were more abundant in more complex forests. The smallest sizes of T. pavo occurred in the most complex forests. On the other hand, our results demonstrated that juvenile fish behaviours were unrelated to the complexity of the Cystoseira forests but mainly related to the body length. The effects of body length on behaviour were however species dependent. Cryptic and transitory behaviours were mostly observed in the smallest and largest juveniles of T. pavo and C. julis, respectively, while the behaviour of Symphodus spp. was unrelated to their body length. Our study emphasises the importance of preserving healthy Cystoseira forests and their intrinsic patchy nature, as this habitat, with its mosaic of different complexity degrees and bathymetrical variability, enable the presence of different fish species at various life stages.

Assessment of net change of productive capacity of fish habitats: the role of uncertainty and complexity in decision making

2003 ◽  
Vol 60 (1) ◽  
pp. 100-116 ◽  
Author(s):  
Charles K Minns ◽  
James E Moore
Keyword(s):  
Decision Making ◽  
Habitat Management ◽  
Fish Habitat ◽  
Productive Capacity ◽  
No Net Loss ◽  
Habitat Linkages ◽  
Fish Habitats ◽  
Fish Response ◽  
Lake Habitats

Canada's fish habitat management is guided by the principle of "no net loss of the productive capacity of fish habitat" (NNL). Many development proposals are assessed using habitat information alone, rather than fish data. Because fish–habitat linkages are often obscured by uncertainty, uncertainty must be factored into NNL assessments. Using a quantitative framework for assessing NNL and lake habitats as a context, the implications of uncertainty for decision making are examined. The overall behaviour of a net change equation given uncertainty is explored using Monte Carlo simulation. Case studies from Great Lakes development projects are examined using interval analysis. The results indicate that uncertainty, even when large, can be incorporated into assessments. This has important implications for the habitat management based on NNL. First, schemas to specify relative levels of uncertainty using simple habitat classifications can support robust decision making. Second, attaining NNL requires greater emphasis on minimizing habitat loss and creating new areas to compensate for losses elsewhere and less on detailing small incremental changes in modified habitats where the fish response is difficult to demonstrate. Third, the moderate to high levels of uncertainty in fish–habitat linkages require that created compensation is at least twice the losses to reasonably ensure NNL.

scholarly journals The role of closed areas in rebuilding monkfish populations in the Gulf of Maine

2008 ◽  
Vol 65 (7) ◽  
pp. 1326-1333 ◽  
Author(s):  
Melissa D. Smith ◽  
Jonathan H. Grabowski ◽  
Philip O. Yund
Keyword(s):  
New England ◽  
Diet Composition ◽  
Gulf Of Maine ◽  
Fish Habitat ◽  
Juvenile Fish ◽  
Habitat Type ◽  
Management Tool ◽  
Feeding Intensity ◽  
Groundfish Fishery

Abstract Smith, M. D., Grabowski, J. H., and Yund, P. O. 2008. The role of closed areas in rebuilding monkfish populations in the Gulf of Maine. – ICES Journal of Marine Science, 65: 1326–1333. The use of fish closures as a management tool to protect juvenile fish habitat and adult spawning grounds has become increasingly popular, although knowledge of the direct effects of marine closures on juvenile fish populations is limited. Given that monkfish landings account for a considerable percentage of the monetary value derived from the groundfish fishery in new England, investigating the factors that influence monkfish population dynamics will assist managers in sustaining this important natural resource. We conducted bottom-trawl surveys to determine the effects of closure status [inside vs. outside the Western Gulf of Maine Closure Area (WGMCA)] and habitat type (mud bottom in isolation from gravel or cobble bottom vs. mud that is next to these more complex habitats) on the distribution, abundance, and diet composition of monkfish (Lophius americanus) in the Gulf of Maine. Surprisingly, the abundance of adult monkfish did not differ in vs. out of the closure, and juvenile monkfish were more abundant outside of the WGMCA, where they also exhibited higher feeding intensity and consumed more prey biomass. Monkfish diet and condition results implied that the boulder and ledge bottom is essential monkfish habitat and that these effects were independent of the WGMCA.

scholarly journals Tropical rhodolith beds are a major and belittled reef fish habitat

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rodrigo L. Moura ◽  
Maria L. Abieri ◽  
Guilherme M. Castro ◽  
Lélis A. Carlos-Júnior ◽  
Pamela M. Chiroque-Solano ◽  
...  
Keyword(s):  
Reef Fish ◽  
Trophic Structure ◽  
Fish Assemblages ◽  
Fish Habitat ◽  
Reef Fishes ◽  
Marine Biodiversity ◽  
Resources Management ◽  
Abundance And Distribution ◽  
Fish Habitats ◽  
Energy Pathways

AbstractUnderstanding habitat-level variation in community structure provides an informed basis for natural resources’ management. Reef fishes are a major component of tropical marine biodiversity, but their abundance and distribution are poorly assessed beyond conventional SCUBA diving depths. Based on a baited-video survey of fish assemblages in Southwestern Atlantic’s most biodiverse region we show that species composition responded mainly to the two major hard-bottom megahabitats (reefs and rhodolith beds) and to the amount of light reaching the bottom. Both megahabitats encompassed typical reef fish assemblages but, unexpectedly, richness in rhodolith beds and reefs was equivalent. The dissimilar fish biomass and trophic structure in reefs and rhodolith beds indicates that these systems function based on contrasting energy pathways, such as the much lower herbivory recorded in the latter. Rhodolith beds, the dominant benthic megahabitat in the tropical Southwestern Atlantic shelf, play an underrated role as fish habitats, and it is critical that they are considered in conservation planning.

scholarly journals Typology of fish nurseries in shallow Mediterranean coastal zones: all habitats matter

2020 ◽  
Author(s):  
Adrien Cheminée ◽  
Laurence Le Direach ◽  
Elodie Rouanet ◽  
Patrick Astruch ◽  
Adrien Goujard ◽  
...  
Keyword(s):  
Species Richness ◽  
Fish Species ◽  
Fish Assemblages ◽  
Juvenile Fish ◽  
Economic Value ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Coastal Zones ◽  
Habitat Types ◽  
Species Richness And Abundance

Abstract Coastal zones are ecosystems of high economic value but exposed to numerous disturbances, while they represent nurseries for many fish species, raising the issue of the preservation of their functions and services. In this context, the juvenile fish assemblages of all types of habitats present in shallow coastal zones were studied on the south-east coast of France using underwater visual censuses. The abiotic and biotic descriptors of the 14 habitat types individualized did not vary with time, except for a higher cover percentage and canopy height of macrophytes in the warm period, which increased the three-dimensional structure of some habitats. The taxonomic composition and density of juvenile fish assemblages were analyzed using both multivariate and univariate descriptors, after grouping the 57 fish species recorded into 41 well-individualized taxa. Juvenile fishes were recorded in all habitat types, with higher mean species richness and abundance during the warm than the cold period. The richest habitats in terms of both species richness and abundance were the natural rocky substrates and the interfaces between Posidonia beds and the other habitats. Although juvenile fish assemblages differed among habitat types and between periods, the most abundant fish species (Atherina sp., Sarpa salpa, Gobiidae, Symphodus spp., Pagellus spp. and several Diplodus species) colonized different habitat types (from 7 to 14) during their juvenile life. This study provided evidence of the role of all types of shallow coastal habitats as fish nurseries and their varying pattern of occupation in space and time by the different juvenile stages. It highlighted the importance of the mosaic of habitats and interfaces for the complete development of all juvenile life stages of fishes, and for the preservation of a high diversity of coastal fish assemblages and fisheries resources in the Mediterranean Sea.

scholarly journals The Role of Sea-Whip Coral (Leptogorgia sp.) as Habitat of Temperate Near-Shore Fish of Gulf of Mexico Jetties

2021 ◽  
Vol 13 (2) ◽  
pp. 17
Author(s):  
Alyssa Squiers ◽  
Kevin B. Strychar
Keyword(s):  
Fish Species ◽  
Fish Habitat ◽  
Abundant Species ◽  
Red Drum ◽  
Stationary Field ◽  
Field Sampling ◽  
Gorgonian Coral ◽  
Near Shore ◽  
Study Component

Many fish species use intercoastal jetties throughout their life cycle to migrate to and from the ocean into bays and estuaries. During migration, fish may encounter rock, algae, sand, sea-grass, and coral. Anecdotal information indicates that some migrating fish of intercoastal jetties preferentially select colonies of gorgonian coral (Leptogorgia spp.) vs. any other habitat when encountering a predator.  Since very little information exists regarding Leptogorgia, we focused our study in determining the importance of such coral as fish habitat.  Stationary field sampling was conducted seasonally to determine the abundance of these coral, the type of migrating fish, and the habitat they associated with.  Mesocosm studies were then conducted to determine whether Leptogorgia habitats are important to fish in the presence or absence of a predator.  Five different habitats were compared (rock, algae, sand, Leptogorgia, and seagrass) and 6 species of fish (sergeant major, pinfish, mangrove snapper, spotfin mojarra, pigfish, and red drum). In the field study component, more than 600 colonies of Leptogorgia were observed and 17 different fish species.  The most commonly observed fish were sergeant major, pinfish, mangrove snapper, and spotfin mojarra, however, sergeant majors were the most abundant species using coral as habitat.  The use of mesocosms showed that all fish species significantly selected for structured habitat over non-structured habitat (e.g. sand), but that the fish commonly called ‘sergeant major’ significantly (ANOVA; p ≤ 0.001) selected for Leptogorgia.

scholarly journals Economic mapping and assessment of Cymodocea nodosa meadows as nursery grounds for commercially important fish species. A case study in the Canary Islands

One Ecosystem ◽  
2021 ◽  
Vol 6 ◽  
Author(s):  
Enrique Casas ◽  
Laura Martín-García ◽  
Francisco Otero-Ferrer ◽  
Fernando Tuya ◽  
Ricardo Haroun ◽  
...  
Keyword(s):  
Ecosystem Services ◽  
Fish Species ◽  
Habitat Suitability ◽  
Economic Value ◽  
Cymodocea Nodosa ◽  
Seagrass Meadows ◽  
Value Transfer ◽  
Suitability Maps ◽  
Commercially Important

Cymodocea nodosa seagrass meadows provide several socio-economically ecosystem services, including nurseries for numerous species of commercial interest. These seagrasses are experiencing a worldwide decline, with global loss rates approaching 5% per year, mainly related to coastal human activities. Cymodocea nodosa, the predominant seagrass in the Canary Archipelago (Spain), is also exposed to these threats, which could lead to habitat loss or even local disappearance. In this case study, we estimated the potential economic value of Cymodocea nodosa seagrass meadows for local fisheries at an archipelago scale. Habitat suitability maps were constructed using MAXENT 3.4.1, a software for modelling species distributions by applying a maximum entropy machine-learning method, from a set of environmental variables and presence and background records extracted from historical cartographies. This model allows characterising and assessing the C. nodosa habitat suitability, overcoming the implicit complexity derived from seasonal changes in this species highly dynamic meadows and using it as a first step for the mapping and assessment of ecosystem services. In a second step, value transfer methodologies were used, along with published economic valuations of commercially-interesting fish species related to C. nodosa meadows. We estimate that the potential monetary value of these species can add up to more than 3 million euros per year for the entire Archipelago. The simplicity of the proposed methodology facilitates its repeatability in other similar regions, using freely available data and hence, being suitable for data-scarce scenarios.

scholarly journals Patterns of small fish distributions in seagrass beds in a temperate Australian estuary

2007 ◽  
Vol 87 (5) ◽  
pp. 1297-1307 ◽  
Author(s):  
Jane E. Jelbart ◽  
Pauline M. Ross ◽  
Rod M. Connolly
Keyword(s):  
Fish Species ◽  
Fish Assemblages ◽  
Juvenile Fish ◽  
Small Fish ◽  
Seagrass Beds ◽  
Estuary Mouth ◽  
Seagrass Cover ◽  
Australian Estuary ◽  
Continuous Beds ◽  
Zostera Capricorni

Beds of the seagrass Zostera capricorni are an integral part of the estuarine landscape along the east coast of Australia, forming an important habitat for juvenile fish. Seagrass beds can vary in their size, shape and patchiness of seagrass cover as well as their distance from the estuary mouth. We tested for a correlation between these features and small fish assemblages in seagrass. Fifteen beds were selected from three size-categories (small, 980 to 2300 m2; medium, 3375 to 4090 m2; and large, 5335 to 6630 m2). We found that the size of beds, the patchiness of seagrass cover and location within the estuary (distance from estuary mouth) were all related to differences in fish assemblages. There were greater densities of fish species in small (10.3 ±0.79 species .net-1) compared to medium (7.6 ±0.6) and large (8.2 ±0.5) beds. This occurred regardless of bed placement within the estuary, its patchiness or time of sampling (day and night). The fish assemblages within seagrass beds also changed as bed distance to estuary mouth increased. Six species had greater densities in beds closer to the estuary mouth, while only two species were in greater densities far from the mouth. Fish assemblages were different between beds with patchy and continuous cover, although total densities of all fish species combined were similar. There were greater densities of four species in continuous beds compared to two species that were greater in patchy beds. Overall, an important finding was that even small patchy seagrass beds contain greater densities of small fish species than larger beds with continuous seagrass cover.

Littoral habitats as major nursery areas for fish species in estuaries: a reinforcement of the reduced predation paradigm

2020 ◽  
Vol 649 ◽  
pp. 219-234 ◽  
Author(s):  
AK Whitfield
Keyword(s):  
Fish Species ◽  
Juvenile Fish ◽  
High Energy ◽  
Global Scale ◽  
Nursery Areas ◽  
Fish Nursery ◽  
Piscivorous Fish ◽  
Dominant Component ◽  
Littoral Habitats

For many decades, the role of estuaries as important nursery areas for fishes was accepted as fact by scientists and environmental managers. At the turn of the 21st century, a question mark was raised in relation to the reduced predation component of the nursery function, with some scientists contending that both large and small piscivorous fish species had access to the estuarine habitats that juvenile fishes in estuaries occupied. If true on a global scale, the nursery designation for these habitats would be compromised and the long-held paradigm that estuaries are important nursery areas for fishes would need to be revised. In this review, I examine the nature of fish nursery areas in estuarine littoral habitats from a mainly predation perspective and, based on a variety of ichthyofaunal and avifaunal studies, come to the conclusion that apart from a few selected estuarine systems, there is limited predation on juvenile fishes in these particular areas. This, coupled with the abundant suitable food resources for juvenile fish from different trophic categories, shelter from high-energy marine wave action and biological connectivity between a variety of submerged and emergent macrophyte communities, renders shallow estuarine littoral areas ideal nursery areas for the juveniles of mostly euryhaline marine fish species, the dominant component of estuarine ichthyofaunas globally. In addition, there are strong indications from the fossil record that these littoral estuarine nursery areas have been functioning since the Devonian, more than 350 million years ago.

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