Tidepool Fish Research Articles

Tidepool fish assemblages of Gorgona Island, Colombian Pacific coast: a local and regional comparison

The ecology of tidepool fishes has been extensively investigated worldwide over the past 40 years. As in many other ecological fields, studies in temperate zones outnumber studies carried out in tropical areas. Here, we document the short-term spatio-temporal variation of a tidepool fish assemblage from the Tropical Eastern Pacific (Gorgona Island, Colombia), compare our data with previous surveys made in 1993 and provide the first latitudinal comparison of tidepool fish assemblages in the Eastern Pacific coast (43°N to 36°S). During April-July 2006, monthly samplings were carried in 18 tidepools located at three sites this Island. A relatively species-rich tidepool fish assemblage (53 species) was found at Gorgona Island. Labrisomidae, Gobiidae and Gobiesocidae were the dominant resident components of this assemblage, whereas Pomacentridae, Muraenidae and Labridae constituted the transient component. Although the same dominant species were observed in surveys from 1993 and 2006, suggesting a high persistence of this assemblage over time, clear differences in the relative abundance of some species were also detected. These differences were partly the result of using different sampling methodologies (rotenone vs clove oil). Comparisons with other studies performed in tropical and temperate areas of the Eastern Pacific coast indicate a clear latitudinal pattern in the composition of these assemblages that correspond to well-documented biogeographic subdivisions of the marine fauna in this region. Further investigation of the ecological role that tidepool fishes play in rocky intertidal and subtidal areas of Gorgona Island and the whole Tropical Eastern Pacific region will benefit our understanding of the functioning of these important coastal ecosystems. Rev. Biol. Trop. 62 (Suppl. 1): 373-390. Epub 2014 February 01.

Testing latitudinal patterns of tidepool fish assemblages: local substrate characteristics affect regional-scale trends

We tested the regional-scale latitudinal patterns of occurrence and community structure of rocky tidepool fishes in relation to local environmental factors, particularly substrate characteristics. Data were derived from intensive field observations conducted on 36 shore sites spread across ca. 1,000 km north–south (24°03′N–32°45′N) in the south-western Japan. While numbers of families, genera, species and individuals per unit area decreased with latitude, these were dependent on substrate types: sites with non-limestone rock substrates tended to harbour larger numbers than limestone sites at the same latitude. Relative abundances of two dominant families (Blenniidae and Gobiidae) varied among sites with weak latitudinal gradients. Species-specific trends of latitudinal distribution were observed in most of the common intertidal fishes, with over half of the species demonstrating substrate-dependent variation. Species composition was clearly different between the Kyushu Island and the Ryukyus and also between limestone and non-limestone sites. Thus, our results clearly demonstrated that the regional-scale latitudinal trends of tidepool fish assemblages were partially dependent on local environmental characteristics (substrate types). Consideration was given to the influences of the Kuroshio Current and other factors including species interactions that might have helped modify observed latitudinal patterns.

Impacts of exotic mangroves and chemical eradication of mangroves on tide pool fish assemblages

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 472:219-237 (2013) - DOI: https://doi.org/10.3354/meps09961 Impacts of exotic mangroves and chemical eradication of mangroves on tide pool fish assemblages Richard A. MacKenzie1,*, Caitlin L. Kryss1,2 1USDA Forest Service, Pacific Southwest Research Station, Institute of Pacific Islands Forestry, 60 Nowelo St., Hilo, Hawaii 96720, USA 2Marine Science Department, University of Hawaii at Hilo, 200 W. Kawili St., Hilo, Hawaii 96720, USA *Email: rmackenzie@fs.fed.us ABSTRACT: Fish were sampled from tide pools in Hawaii to determine how exotic mangroves Rhizophora mangle and the use of herbicides to chemically eradicate them are impacting tide pool fish assemblages. Ecological parameters were compared among mangrove-invaded, native vegetated, and non-vegetated tide pools before and after mangroves had been chemically eradicated. Native fish densities were higher than exotic fish densities in all treatments, were dominated by flagtails Kuhlia xenura, did not differ among treatments, and 1 yr after herbicidial eradication of mangroves, were greater than or equal to pre-control densities. Exotic fish densities did not differ between mangrove and native vegetated tide pools, were dominated by mollies Poecilia sp., were significantly lower in non-vegetated vs. vegetated pools, and did not differ before and after mangrove eradication. Significantly smaller native flagtails and exotic mollies were present in mangrove tide pools than in all other treatments. Our data suggests that exotic mangroves in Hawaii are not having an adverse effect on native fish assemblages in tide pools, and may actually provide nursery habitat for native and exotic fish. Furthermore, the presence of vegetation and not its origin may be more influential on exotic fish assemblages. Finally, our data suggests that if chemical eradication of mangroves negatively affected tide pool fish assemblages, those effects are short-lived. Future studies should attempt to quantify the ecological value of native versus exotic vegetation in supporting native (or exotic) fish assemblages. KEY WORDS: Rhizophora mangle · Invasive species · Non-native species · Nursery habitat · Kuhlia xenura · Poecilia · Hawaii · Pacific Island Full text in pdf format PreviousNextCite this article as: MacKenzie RA, Kryss CL (2013) Impacts of exotic mangroves and chemical eradication of mangroves on tide pool fish assemblages. Mar Ecol Prog Ser 472:219-237. https://doi.org/10.3354/meps09961 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 472. Online publication date: January 09, 2013 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2013 Inter-Research.

Species and size matter: An experimental study of microhabitat use under the influence of competitive interactions in intertidal gobiids

Patterns of microhabitat use and biotic interactions were examined under experimental conditions using three intertidal gobies, Bathygobius fuscus, Chaenogobius annularis and C. gulosus. A series of microhabitat choice experiment was conducted to document microhabitat utilisation, spatial use overlap and occurrence of agonistic behaviour in single-individual and mixed-individual setups using two size-categories of the three species. Patterns of habitat utilisation as observed under single-individual conditions were significantly modified in the presence of another individual, depending on species identity, body size and time of day. Chaenogobius species showed marked changes especially when paired with a large individual, occurring more frequently outside the shelter and using those substrates that were infrequently used by the paired individual. In contrast, B. fuscus did not show marked changes. Observed (realised) overlap in spatial use under mixed-individual conditions was significantly smaller than the expected overlap based on single-individual conditions (i.e. without any biotic interactions). Marked departures from expected patterns were detected for intra- and inter-specific combinations of Chaenogobius species: there were effects of biotic interactions. C. gulosus rarely showed direct aggression, in contrast to other species, though it exerted an apparent influence on the microhabitat use of a paired species/individual. The occurrence of aggression was different among species pairs and times of day. Body size differences affected the outcome of a contest, but not the occurrence of behaviour itself. The pattern also varied depending upon species combinations and times of day. Fish activity was also influenced by the presence of a paired individual in some cases. The present study revealed that species identity and body sizes are important elements of biotic interactions that affect the patterns of habitat utilisation in these fishes. Such diverse and subtle manners of interaction and habitat use may contribute to species coexistence in tidepool fish assemblages.

Spatial and vertical patterns in the tidepool fish assemblage on the island of O`ahu

The microtides, wave regimes, and relative isolation of the Hawaiian archipelago may provide unique environmental and biogeographic effects that shape the structure of tidepool fishes. We sampled fishes across a narrow gradient at low tide from 6 sites on the island of O`ahu. We tested predictions of the hypotheses that environmental conditions (pool depth, volume, macroalgal cover, temperature, and salinity) would result in a vertically structured tidepool fish assemblage unique to basalt or limestone rocky shores. 343 fish were recorded from 40 pools, and 19 species from 10 families were identified. Tidepool fish diversity (H’: O`ahu = 2.4; Sites Average = 0.0–0.9) was typical for tropical islands, with members from Gobiidae (5 species), Blenniidae (4 species), Pomacentridae (3 species), Acanthuridae (2 species) and Kuhliidae (2 species) among the most common. Endemism (32%) was higher than other well studied assemblages yet similar to Hawaiian reef fishes (25%). Assemblage abundance varied among shores with basalt or limestone substrate, among sites, and vertically among high, mid, and low pools. In general, blenniids occurred at higher proportions on limestone shores and gobiids were more common on basalt shores. High pools were characterized by an abundance of a small sized (29.0 mm median standard length) blenniid Istiblennius zebra, while the blenniid Entomacrodus marmoratus and wrasses Thalassoma spp. were more common in low pools. Temperature was the best environmental predictor of assemblages and this relationship warrants further investigation. Our findings indicate that assemblages can vary across a narrow geographical range and intertidal shore.

Analysis of spatial niche structure in coexisting tidepool fishes: null models based on multi-scale experiments

1. Fundamental and realized spatial niches were investigated through a combination of laboratory and mesocosm experiments, field observations and null model analysis in three intertidal gobiid species (Bathygobius fuscus, Chaenogobius annularis and C. gulosus). Null models based on the results of single-species experiments were used to assess interspecific spatial use and coexistence on two different scales: (i) microhabitats within a tidepool ('microhabitat' scale); and (ii) distribution among a set of tidepools ('habitat-wide' scale). 2. Patterns of microhabitat use varied from single to paired treatments, depending on paired species. Realized overlap of microhabitat use was smaller than would be expected from single-individual situations for intraspecific combinations, but not for interspecific ones. 3. Patterns of tidepool occupancy (a measure of spatial niche breadth) in the mesocosm were influenced by interspecific interactions. Two Chaenogobius species, but not B. fuscus, decreased tidepool occupancy in the hetero-specific treatments compared with the mono-specific ones. For all interspecific combinations, spatial overlap (habitat-wide scale) was significantly lower than the values expected from mono-specific situations. The results also indicated a possible trade-off between competitiveness and growth efficiency in these fishes. 4. Interspecific spatial overlap in the field was similar to that in the mesocosm experiment and the pattern of coexistence of gobiids can be explained by the results of our experiments. 5. This study demonstrates that niches of intertidal fishes may experience modifications under the influence of species interactions and that null models based on controlled experiments can greatly facilitate the deciphering of such changes in niche structure.

Local v. microhabitat influences on the fish fauna of tidal pools in north‐east Brazil

This study explored the influence of microhabitat characteristics, such as sandy, rocky and algal bottom, holes, area and depth, on tide-pool fish descriptors (evenness, total number of fish, diversity and species richness). Even when the rockpool microhabitats differed amongst beaches, the tidal fish assemblages were closely grouped by site rather than by characteristics of the tide pools. Fish assemblages were mostly represented by juvenile fishes from 29 species, of which 14 were observed in only one of the three sites. This indicates that sites, rather than microhabitat association, might play a major role for the rockpool ichthyofauna in north-east Brazil.

Comparative analysis of tidepool fish species composition on tropical coastal rocky reefs at State of Ceará, Brazil

This study compared tidepool fish assemblages within and among habitats at Iparana and Pecém beaches, State of Ceará, Northeast Brazil, using visual census techniques. A total of 8,914 fishes, representing 25 families and 43 species were recorded. The most abundant taxon was Sparisoma spp, followed by Haemulon parra (Desmarest, 1823), Acanthurus chirurgus (Bloch, 1787) and Abudefduf saxatilis (Linnaeus, 1758). Haemulidae was the most abundant family in number of individuals, followed by Scaridae, Acanthuridae and Pomacentridae. Within- and between- site differences in species assemblages probably reflected environmental discontinuities and more localized features, such as pool isolation episodes, or environmental complexity, both acting isolated or interactively. The locality of Iparana was probably subjected to a greater fishing pressure and tourism than Pecém, a potential cause for the observed lowest fish abundance and biodiversity. We conclude that tidepool ichthyofauna may be quite variable between and within reef sites. Thus, observations taken from or damages caused on one area may not be generalized to or mitigated by the protection of adjacent sites.

Food resource use in a tropical eastern Pacific tidepool fish assemblage

An understanding of the trophic organization patterns of tropical littoral fish assemblages can contribute to the knowledge of key ecosystem processes while simultaneously assisting to validate large-scale biogeographic patterns (i.e. latitudinal patterns in fish herbivory). In the present study, the diets of eight fish species inhabiting the tide pools of a rocky shore on the western coast of Colombia (tropical eastern Pacific) are documented. A total of 17 prey items were identified, with a major representation (average percent by weight) of crabs and macroalgae items in the guts of all species. Small crustacean prey items (crabs, shrimps, copepods and amphipods) dominated the diets of most species, but consumption of macroalgae and diatoms by a significant number of species was also observed. We identified four significant trophic guilds within the assemblage using multivariate techniques (cluster analysis and nMDS): an omnivorous guild, consisting of Malacoctenus zonifer and the smallest size class of Bathygobius ramosus; a small-prey carnivorous guild, consisting of the intermediate size classes of B. ramosus and the smallest size class of Gobiesox adustus; a large-prey carnivorous guild, consisting of both largest size classes of B. ramosus and G. adustus; and an herbivorous guild consisting of Abudefduf concolor, A. troschelii and Chaenomugil proboscideus. The diet of two species slightly overlapped those of the rest of the assemblage and did not conform to any guild (Echidna nocturna and Halichoeres aestuaricola). It is hypothesised that guild formation may be a consequence of aggregation of species at abundant resources in the intertidal zone rather than a direct consequence of inter-specific competition. Ontogenetic changes in diets were observed in two resident species of the assemblage (B. ramosus and G. adustus). The latitudinal trend for herbivory inside this tropical assemblage is discussed in comparison with similar temperate studies in the eastern Pacific.

Persistent regional variation in populations of a tidepool fish

Understanding the factors that drive population dynamics is particularly challenging in systems that are connected via propagule dispersal because the rate of arrival of new individuals is both notoriously unpredictable and potentially critical in determining future dynamics. Furthermore, patterns of propagule recruitment can be fundamentally modified by post-recruitment interactions. We investigated how variation in both the recruitment of juveniles and local community structure affected the demography of an intertidal fish in two oceanographically distinct regions in Oregon. From 2001–2003, we observed persistently higher densities of adult tidepool fish Clinocottus globiceps (Girard) at Cape Foulweather, a stronger-upwelling region compared to Cape Perpetua, a weaker-upwelling region. In 2002, recruitment was roughly two times higher in the Cape Perpetua region. By the following spring, densities of adults were more than three times higher in the Cape Foulweather region, implicating intense post-recruitment mortality in the Cape Perpetua region as the cause of regional differences in adult densities. We manipulated, using a factorial experimental design, the presence and absence of dominant sessile organisms in tidepools at one site in each region in the spring of 2002 and explored whether differences in tidepool communities could be related to regional variation in fish abundance. Fish recruited disproportionately to pools with low cover of mussels in both regions. By the following spring, adults were more abundant in pools with mussels in one region and equally abundant in pools with or without mussels in the other region. Possible explanations for regional differences in C. globiceps populations include regional variation in the cover of intertidal invertebrates, in local biological interactions such as predation, or in coastal bathymetry that may be linked to variation in physical processes controlling recruitment and over-winter survival.

Temporal and spatial variations in tidepool fish assemblages of the northeast coast of Brazil

Temporal and spatial variations and environmental factors influencing the structure of tidepool fish assemblages were quantitatively investigated at Iparana beach, northeast Brazilian coast. The majority of the tidepool fishes sampled were suprabenthic juvenile individuals of great mobility. We recorded during monthly diurnal underwater visual censuses a total of 4,750 fish from 26 species, represented mainly by partial residents from the families Scaridae, Haemulidae, Gerreidae and Pomacentridae. The number of species and individuals showed significant variability among tidepools as a response to variations in their volume and type of substrate cover. The greatest species abundance and richness associated with rocks covered with algae suggested that substrate complexity is one of the main factors defining the spatial structure of the tidepool ichthyofauna. Temporal variability in species abundance and richness was associated with changes in salinity levels due to seasonal rainfalls. A higher number of juvenile fishes from December to May in our samples corroborate the hypothesis that the tidepools act as nursery sites. Therefore, the species associations found in this study and their relation to seasonal and spatial discontinuities may be partly explained according to their habitat requirements and reproductive cycles.

Short-Term Dynamics of Tidepool Fish Community: Diel and Seasonal Variation

Short-term temporal dynamics in a tidepool fish community were quantitatively examined through a series of direct observation at consecutive low tides in a temperate-subtropical intertidal of southwestern Japan. The visual observation was sufficiently effective compared with the capture by anaesthetics and allowed a continual, undisturbed monitoring. Species composition markedly varied between consecutive day versus night in spring-autumn, but not in winter. In contrast, species composition on consecutive days and on consecutive nights was relatively stable all through the year. The pattern of diel change in abundance varied among species and seasons. C. gulosus, Istiblennius sp. and Girella spp. showed the tendency of night-time occurrence, while B. fuscus individuals tended to occur by day. These trends of day–night differences were mainly observed in spring and summer and rarely in winter. Size differences between day and night were detected in B. fuscus, C. gulosus, Istiblennius sp. and Girella spp. This tidepool fish community demonstrated variation in abundance and body size on short time scales, which may be attributable to behavioural differences among species.

Community structure of an assemblage of tidepool fishes on a tropical eastern Pacific rocky shore, Colombia

The composition, abundance, species richness and diversity of a rocky intertidal fish assemblage in the central zone of the Pacific coast of Colombia were determined. From July to December 2002, 10 tidepools with volumes ranging from 0·087 to 1·350 m3 were surveyed. A total of 893 fishes belonging to 14 species and 12 families were found. The most abundant species were Bathygobius ramosus and Abudefduf concolor, representing 71% of all fishes collected. Bathy gobius ramosus, Malacoctenus zonifer and Gobiesox adustus were residents, Abudefduf concolor, Abudefduf troschelii, Microsphatodon bairdii, Chaenomugil proboscideus, Halichoeres aestuaricola and Echidna nocturna were transients, and Apogon dovii, Sargocentron suborbitalis, Cerdale sp, Rypticus nigripinnis and Ctenochaetus marginatus were considered as accidental visitors. The temporal and spatial variation of assemblage structure was tested. The fish assemblage structure did not differ between months and there was not a clear relationship between tidepool surface area and depth, and community variables. Diversity and species richness were negatively correlated with tidepool height. It is suggested that the tidepool assemblage was stable and resilient in time on short (annual) scales. The constancy in time and space could have been a consequence of eurytopic features of the organisms and the lack of drastic seasonal changes in the tropics.

Ultraviolet-absorbing compounds in the mucus of temperate Pacific tidepool sculpins: variation over local and geographic scales

Temperate tidepool fishes of the family Cottidae (Teleostei) display biogeographic dis- tribution patterns that vary with latitude and elevation within the intertidal zone. Middle and high intertidal pool species show a pattern of 'species replacement', with southern species being replaced by northern species at discrete locations along the coast. Lower intertidal pools, on the other hand, are dominated by a single species, Oligocottus snyderi, that occurs over an extremely wide latitudi- nal range. As a consequence of both latitudinal and elevational patterns, these fish experience vari- able amounts of ultraviolet (UV, 280 to 400 nm) irradiation both between and within species. The mucus of tidepool sculpins was analyzed by absorbance spectrophotometry to compare concentra- tions of UV-absorbing compounds in the mucus of fish, with regard to geographic location or inter- tidal microhabitat. Mucus from northerly fishes absorbed significantly less UV than the mucus of southerly fishes. Overall, mucus from high intertidal pool fishes absorbed significantly more UV than mucus from middle or lower intertidal pool fishes, but differences were not detectable within a site. The mucus spectra of all fish surveyed contained a single UV absorption peak with maximum absorbance (λmax) in the short-wavelength UVA (UVA = 320 to 400 nm, λmax range = 323 to 331 nm). Compounds with λmax in the UVB (280 to 320 nm) or longer-wavelength UVA (ca. 360 nm) were not found, although these compounds were present in 38 (UVB) and 59% (longer UVA) of tropical species' mucus (138 species surveyed).

Diel Changes in Habitat Use by Two Tidepool Fishes

Abstract I examined the effects of low-tide timing on tidepool use by two southern California fishes, Clinocottus analis and Girella nigricans. Abundance of these fishes in middle and upper intertidal pools was higher when low tides occurred at night or in the early morning (4.4–9.7 fish per pool) than in the afternoon (1.3–3.4 fish per pool). Mean fish size was also higher during nighttime low tides than daytime low tides. Tidepools higher in the intertidal zone generally displayed greater differences in fish abundance between early morning and afternoon low tides than lower pools. In addition, these upper tidepools reached higher temperatures during afternoon low tides (up to 30 C) than lower tidepools, often exceeding or nearing the preferred and lethal maximum temperatures reported for the two study species. Diel vertical habitat shifts by middle and upper tidepool fishes indicate that their partitioning of rocky intertidal habitat occurs on short-term temporal as well as spatial scales.

APPEARANCE AND POSSIBLE HOMING OF TWO SPECIES OF SCULPINS IN MAINE TIDEPOOLS

Two species of sculpins (Cottidae), the grubby, Myoxocephalus aenaeus, and the shorthorn sculpin, M. scorpius, were studied in rocky tidepools along the coast of Maine. Fishes were captured and measured during 116 sampling trips between 1979 and 1996. Both of these species of sculpins are from the northwestern Atlantic Ocean and are present in tidepools nearly every month of the year and are the only fish species found in Maine tidepools during winter. Both sculpin species are important components of tidepool ecosystems and dominate the rocky tidepool fish communities from late autumn to early spring, a time when other fish species decline in abundance or are absent. There was no apparent relationship between sculpin abundance and salinity, but the two species of Myoxocephalus were encountered in water temperatures of 1.5 to 18.9°C, with 55.0% of the shorthorn sculpins and 57.3% of the grubbies encountered in tidepools where water temperatures ranged from 12 to 15°C. Between 1988 and 1996, 102 individuals from both species were marked. Of these, 21.3% were recaptured, some repeatedly in the same tidepools and even at specific locations within tidepools over successive tidal cycles—an indication of homing behavior.

Changes in a tidepool fish assemblage on two scales of environmental variation: Seasonal and El Niño Southern Oscillation

Intertidal organisms are influenced by the tidal, daily, and seasonal environmental variability of their habitat. Interannual variability, although often less severe than shorter‐scale variability, may also be important in structuring intertidal systems. This study compares the magnitude of changes in a rocky intertidal fish guild occurring on a seasonal scale with those occurring during an El Niño Southern Oscillation (ENSO). I examined tidepool fish assemblage structure and habitat use in two southern California sites approximately every 3 months from 1996 to 2000, a period including non‐ENSO conditions, the 1997–1998 El Niño, and the 1998–1999 La Niña. During each sampling period, I censused fish abundance in 105 tidepools of differing intertidal height, depth, and surface area. Several aspects of habitat use varied seasonally for the four most common species: Clinocottus analis (woolly sculpin), Girella nigricans (opaleye), Gobiesox rhessodon (California clingfish), and Hypsoblennius gilberti (notch‐brow blenny). All four species migrated vertically within the intertidal zone on a seasonal scale, corresponding to seasonal changes in sea level. The assemblage dominant, C. analis, occupied tidepools of different sizes depending on season. Although seasonality in habitat use suggests an influence of environmental variability on seasonal scales, fish habitat was generally not altered by temperature and sea level changes imposed by the El Niño. Species assemblage, however, differed among climate conditions. C. analis declined in abundance during the El Niño because of lack of recruitment but increased immediately after its conclusion. Paraclinus integripinnis (reef finspot), usually rare, was more abundant during the El Niño. Effect of the El Niño on the other four species was not detected. Assemblage changes suggest that although intertidal fishes regularly experience large tidal, daily, and seasonal environmental fluctuations, interannual changes in environmental factors, even when relatively small in magnitude, can perturb the system. Perturbations in the present system, however, did not persist beyond the end of the El Niño event as they often do in lower‐latitude nearshore areas.

Spatial and seasonal patterns of habitat partitioning in a guild of southern California tidepool fishes

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 196:253-268 (2000) - doi:10.3354/meps196253 Spatial and seasonal patterns of habitat partitioning in a guild of southern California tidepool fishes Jana L. D. Davis* Scripps Institution of Oceanography, 9500 Gilman Drive 0208, San Diego, California 92093-0208, USA *E-mail: jana@ucsd.edu ABSTRACT: Five species of fish, Clinocottus analis, Girella nigricans, Hypsoblennius gilberti, Gobiesox rhessodon, and Gibbonsia elegans, commonly occur in southern California¹s rocky intertidal zone. To examine the extent to which tidepool habitat is segregated by the 5 fishes, habitat partitioning patterns among and within the species were determined at 2 sites in San Diego. Fish density, species composition, and fish size were measured in 105 tidepools every 3 mo from November 1996 to August 1997. Hypotheses were tested pertaining to the segregation of habitat among different species and different size classes within species relative to the tidepool characteristics of intertidal height, surface area, depth, rugosity, and percent algal cover. A manipulative field experiment was conducted to further investigate these results. Tidepools were partitioned among and within fish species. Tidepool characteristics most important in partitioning were intertidal height, depth, and rugosity, with the order of importance of these characteristics different for each species. Habitat partitioning between size classes within species, although not as great as partitioning among species, was also based largely on tidepool intertidal height and rugosity. Although fish abundance changed seasonally, species¹ distribution patterns, with the exception of C. analis, were seasonally stable. The seasonal change in C. analis distribution was due to the arrival of new recruits rather than a seasonal change in adult habitat. The use of different types of tidepools by different species and by different size classes within species serves to limit contact among these groups, and therefore both direct and indirect competition, during low tide. KEY WORDS: Fish · Rocky intertidal zone · Clinocottus analis · Girella nigricans · Hypsoblennius gilberti · Gobiesox rhessodon · Gibbonsia elegans Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 196. Publication date: April 18, 2000 Print ISSN:0171-8630; Online ISSN:1616-1599 Copyright © 2000 Inter-Research.

Variation and resilience of rocky intertidal fish in western Portugal

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 184:197-203 (1999) - doi:10.3354/meps184197 Variation and resilience of rocky intertidal fish in western Portugal Claudia Faria*, Vitor Almada Unidade de Investigação em Eco-Etologia, Instituto Superior de Psicologia Aplicada, R. Jardim do Tabaco, 34, P-1100 Lisboa, Portugal *E-mail: cfaria@ispa.pt ABSTRACT: A monthly census of resident fishes in tide pools was made at 3 sites on the Portuguese west coast, from 1993 to 1997. A total of 43 tide pools was monitored. Results of manipulation (addition and removal) experiments are presented. There is a very high level of consistency in the numbers of species at 1 site. Experiments on removal and addition show that the number of fish in the pools returns to normal in a few weeks. The inter-annual fluctuations of recruitment are less pronounced as the fish grow, possibly due to density dependent mortality. At the other 2 sites, where the pools are disturbed by storms that reshape their contents and move large quantities of sand, there is a less consistent pattern. The agonistic behaviour of tide pool fishes is strongly related to the priority of access to holes and crevices and this may place limits on the number of fishes of a given size that can exist in each pool as a function of topographic complexity. KEY WORDS: Intertidal fishes · Resilience · Inter-annual variations · Fish communities Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 184. Publication date: July 28, 1999 Print ISSN:0171-8630; Online ISSN:1616-1599 Copyright © 1999 Inter-Research.

Extinction, colonization, and species occupancy in tidepool fishes

Despite the increasing sophistication of ecological models with respect to the size and spatial arrangement of habitat, there is relatively little empirical documentation of how species dynamics change as a function of habitat size and the fraction of habitat occupied. In an assemblage of tidepool fishes, I used maximum-likelihood estimation to test whether models which included habitat size provided a better fit to empirical data on extinction and colonization probabilities than models that assumed constant probabilities over all habitats. I found species differences in how extinction and colonization probabilities scaled with habitat size (and hence local population size). However, there was little evidence for a relationship between extinction and colonization probabilities and the fraction of occupied tidepools, as assumed in simple metapopulation models. Instead, colonization and extinction were independent of the fraction of occupied tidepools, favoring a MacArthur-Wilson island-mainland model. When I incorporated declines in extinction probability with tidepool volume in a simple simulation model, I found that predicted occupancy could change greatly, especially when colonization was low. However, the predicted fraction of occupied patches in the simulation model changed little when I incorporated the range of values reported here for extinction and colonization and the rate at which they scale with habitat size. Quantifying extinction and colonization patterns of natural populations is fundamental to understanding how species are distributed spatially and whether metapopulation models of species occupancy provide explanatory power for field populations.