Intertidal Pools Research Articles

Response of native and invasive grazers to global warming: marine heatwaves vs. gradual trends

Ecological responses to global warming are likely driven by a combination of gradual warming trends and extreme climate events, which are increasing in frequency and intensity. Specifically, heatwaves may amplify the impact of ongoing warming, and thus affect species’ physiological responses, behaviour and eventually survival. Here, we tested the hypothesis that a tropical invasive grazer snail, Cerithium scabridum, will be more resilient to the effects of future gradual warming and marine heatwaves (MHWs) than its native congener C. lividulum, co-occurring in rocky intertidal pools along the Levantine coast. Survival and faecal production (as a proxy for feeding rate) of the 2 species were measured under 4 experimental temperature conditions: ambient summer mean (31°C), predicted warming scenario (ambient +3°C), and short-term MHWs (+5°C) added to either ambient or warming treatments, followed by a recovery period. No effect of warming alone was detected on either species, whereas MHW reduced faecal production only in the native C. lividulum. During the recovery period, C. lividulum survival dropped, but the few surviving individuals recovered from the heat stress as indicated by the increase in faecal production. Neither snail species survived under the combination of warming and MHW. These results suggest that both species, living in a thermally fluctuating and often extreme environment, can tolerate a +3°C gradual warming, but only the invasive snail can withstand a +5°C heatwave. However, neither species can endure a severe heatwave on top of predicted gradual warming, potentially leading to population collapse among both species in the region.

Associating the Moon and the tide

Abstract The Moon is important to us. It has played a major role in the evolution of our planet, most obviously by causing a reduction of the rotation rate of the Earth through tidal friction. It is even possible that the Moon and hence the tides could have provided one mechanism for the origin of life on Earth through the repeated flooding and drying out under the Sun of primitive organisms in inter-tidal pools [1], [2]. In addition, the Moon has been an important factor in the religions and cultures of many societies.

Assessment of anthropogenic particles in Holothuria sanctori from Tenerife (Canary Islands, Spain)

Sea cucumbers play a key role in maintaining the health of coastal marine ecosystems. The aim of this research was to evaluate the presence of anthropogenic particles in sea cucumbers of the species Holothuria sanctori in intertidal pools from Tenerife (Canary Islands, Spain) and in the surrounding seawater. In the case of sea cucumbers (n = 18), the gastrointestinal tract (particles ingested directly from the sediment) and Cuvierian tubules (particles presence as a result of gas exchange with seawater) were analysed separately. Anthropogenic particles were found in all samples, with an average concentration of 20.0 ± 4.4 items per litre in seawater and 11.8 ± 3.9 items per individual in the sea cucumbers, with a higher concentration of particles in the gastrointestinal tract (9.3 ± 3.4 items per gastrointestinal tract) than in the Cuvierian tubules (2.6 ± 3.3 items per Cuvierian tubules). Transparent and blue microfibres were predominant, accounting for over 90 % of the samples analysed. A significant proportion of these fibres were of cellulosic origin (either natural or semisynthetic, comprising 78.7 %), while fully synthetic polymers (microplastics), were also identified, including polyester and polyvinyl chloride (the latter exclusively detected in seawater).

Caracterización de las comunidades ícticas de charcos intermareales en la isla de Tenerife

The island of Tenerife has experienced significant population growth and urban development in coastal areas, resulting in a negative impact on the ichthyic communities associated with its intertidal pools, which act as a refuge and nursery for a large number of species, many of them of fishing interest. In order to characterize these populations and know their conservation status, sampling was carried out using baited remote underwater video (BRUV) in four areas in Tenerife located on the north coast, Punta del Hidalgo and Finca El Apio, and on the south, Las Galletas and Punta Rasca. A total of 13 fish species were found throughout the sampling, 7 of them of fishing interest in the Canary Islands. According to the results obtained, a significant variation can be seen between the communities of the sampled localities. Specifically, it was observed that Punta del Hidalgo has the highest fish abundance and richness of species. On the other hand, it was found that the locality of Las Galletas differs significantly from the rest, presenting a low abundance of species, especially those of fishing interest.

Patrones de cambios cromáticos en juveniles y adultos de la castañeta Nexilosus latifrons (Cichliformes: Pomacentridae)

Patterns of temporal chromatic and shape variations of live specimens of Nexilosus latifrons were studied. Observations were made on specimens captured in intertidal pools in the coastal area of Arica, northern Chile, which were kept in captivity for 16 months. Five developmental stages, in which there were noticeable changes in shape and colouration, were described. Findings obtained primarily to improve species identification are discussed, as well as to prevent removal of juvenile specimens from the environment and improve captive breeding practices.

Ocean acidification enhances primary productivity and nocturnal carbonate dissolution in intertidal rock pools

Abstract. Human CO2 emissions are modifying ocean carbonate chemistry, causing ocean acidification and likely already impacting marine ecosystems. In particular, there is concern that coastal, benthic calcifying organisms will be negatively affected by ocean acidification, a hypothesis largely supported by laboratory studies. The inter-relationships between carbonate chemistry and marine calcifying communities in situ are complex, and natural mesocosms such as tidal pools can provide useful community-level insights. In this study, we manipulated the carbonate chemistry of intertidal pools to investigate the influence of future ocean acidification on net community production (NCP) and calcification (NCC) at emersion. Adding CO2 at the start of the tidal emersion to simulate future acidification (+1500 µatm pCO2, target pH 7.5) modified net production and calcification rates in the pools. By day, pools were fertilized by the increased CO2 (+20 % increase in NCP, from 10 to 12 mmol O2 m−2 h−1), while there was no measurable impact on NCC. During the night, pools experienced net community dissolution (NCC < 0), even under present-day conditions, when waters were supersaturated with regard to aragonite. Adding CO2 to the pools increased nocturnal dissolution rates by 40 % (from −0.7 to −1.0 mmol CaCO3 m−2 h−1) with no consistent impact on nocturnal community respiration. Our results suggest that ocean acidification is likely to alter temperate intertidal community metabolism on sub-daily timescales, enhancing both diurnal community production and nocturnal calcium carbonate dissolution.

New records of ray-finned fishes (Actinopterygii) from Puerto Morelos Reef National Park (Mexican Caribbean)

We documented the nearshore ray-finned fishes in Puerto Morelos Reef National Park (PMRNP) by sampling 57 localities, including rocky intertidal pools, sandy bottoms, Thalassia beds, coral reefs, artificial reefs, karstic-slab bottoms, demersal-pelagic areas, and sessile-Sargassum patches. We recorded seven species new to Caribbean Mexican waters and one hundred and six species new to the PMRNP, most of which are small cryptobenthic reef fish. The resultant checklist includes 349 species, and specimens of 285 of which (81.7%) have been deposited in an ichthyological museum collection. These include both voucher organisms and with tissue samples for genetic analysis. A comparison with inventories at other localities of the Greater Caribbean indicates that more targeted sampling for cryptobenthic and deep-reef fishes is needed to provide a complete inventory. We also comment on the local use of some species as fishery resources.

Physicochemical origins of prokaryotic and eukaryotic organisms.

Origins research currently rests on a vitalistic foundation and requires reconceptualization. From a cellular perspective, prokaryotic cells grow and divide in stable, colloidal processes, throughout which the cytoplasm remains crowded (concentrated) with closely interacting proteins and nucleic acids. Their functional stability is ensured by repulsive and attractive non-covalent forces, especially van der Waals forces, screened electrostatic forces, and hydrogen bonding (hydration and the hydrophobic effect). On average, biomacromolecules are crowded at above 15% volume fraction, surrounded by up to 3 nm layer of aqueous electrolyte at ionic strength above 0.01 molar; they are energized by biochemical reactions coupled to nutrient environments. During cellular growth, non-covalent molecular forces and biochemical reactions stabilize the cytoplasm as a two-phase, colloidal system comprising vectorially structured cytogel and dilute cytosol. From a geochemical perspective, Earth's rotation kept prebiotic molecules in continuous cyclic disequilibria in Usiglio-type intertidal pools, rich in potassium and magnesium ions, the last cations to precipitate from evaporatig seawater. These ions impart biochemical functionality to extant proteins and RNAs. The prebiotic molecules were repeatedly purified by phase separation in response to tidal drying and rewetting; they were chemically evolving as briny, carbonaceous inclusions in tidal sediments until the crowding transition allowed chemical evolution to proceeed toward Woesian progenotes, the Last Universal Common Ancestors (LUCAs) and the first prokaryotes. These cellular and geochemical processes are summarized as a jigsaw puzzle of the emerging and evolving prokaryotes. Their unavoidable cyclic fusions and rehydrations along Archaean coastlines initiated the emergence of complex Precambrian eukaryotes.

Perils of drifting encapsulated embryos of the periwinkle Littorina scutulata from failures at launch and unscheduled landings

Unusually for benthic animals, mothers in many species of littorinid snails release drifting egg capsules that experience hazards of either the plankton or seafloor. At a site sheltered from large waves, numerous egg capsules of Littorina scutulata remained in high intertidal pools near mothers, and the embryos died. Mortality was also high for embryos in capsules caught in high intertidal clumps of algae. Capsules in shallow water were at early cleavage stages, indicating exposure to intertidal predators only for the hours of early development. In the laboratory, small intertidal pagurid hermit crabs and grapsid crabs ate capsules, and barnacles captured capsules, though with ingestion uncertain. An anemone and a mussel were not hazards. Embryos in capsules exposed to microbial and physical hazards on submerged sediments suffered little mortality, in contrast to previously observed high mortality at the same site for embryos of an echinoid. Predation rates could not be estimated for any location, but other hazards were less on low intertidal and subtidal sediments than in the high intertidal zone. The number of embryos per capsule and capsule sizes varied within a mother’s spawn, between spawns of mothers of similar size, and with maternal condition. Packaging several embryos in a capsule did not increase sinking speeds much beyond sinking reported for planktonic single unhatched blastulae in other taxa. Some embryos died through failure to launch, but capsules provided low sinking speeds during drift, brief residence in shallow intertidal waters, and protection from microbial and chemical hazards on sediments when sunk.

Tidal migrations of juvenile Sillago spp. in a subtropical intertidal nursery seascape

Context Subtropical intertidal pools on depositional shores are important nursery habitats for smaller juveniles (10- to ~25-mm total length, TL) of commercially important smelt whiting (Sillago spp.), whereas larger juveniles >25 mm TL occupy shallow subtidal habitats at low tide. Aims We investigated the connectivity between lower and upper shore habitats in Moreton Bay. Methods We used funnel camera traps to assess tidal movements of juvenile whiting and compared harpacticoid copepod genera in small juvenile whiting guts caught post-foraging with those sampled from nearby sediments to infer patterns of foraging. Key results Smaller juveniles transited sandy upper-shore habitat at depths from 1.5 to <10 cm and avoided vegetated habitats, whereas larger juveniles moved into mangroves at depths of 15–30 cm on the rising tide. Coullana spp. harpacticoids were found in greater proportions in whiting guts of small juveniles than in the sampled habitats, but were abundant in intertidal pool and mangrove sediments. Conclusions Intertidal sandy habitats are seemingly an important high-tide habitat for smaller juvenile whiting, where they preferentially forage on Coullana spp. Implications Given the broad distribution of smelt whiting in the Indo-Pacific, the protection of such habitats must be addressed by fishery and habitat management agencies for species with similar early nursery requirements.

Structure and formation of the perforated theca defining the Pelagophyceae (Heterokonta), and three new genera that substantiate the diverse nature of the class.

The pelagophytes, a morphologically diverse class of marine heterokont algae, have been historically united only by DNA sequences. Recently we described a novel perforated theca (PT) encasing cells from the Pelagophyceae and hypothesized it may be the first morphological feature to define the class. Here we consolidate that observation, describing a PT for the first time in an additional seven pelagophyte genera, including three genera new to science. We established clonal cultures of pelagophytes collected from intertidal pools located around Australia, and established phylogenetic trees based on nuclear 18S rDNA and plastid rbcL, psaA, psaB, psbA and psbC gene sequences that led to the discovery of three new species: Wyeophycus julieharrissiae and Chromopallida australis form a distinct lineage along with Ankylochrysis lutea within the Pelagomonadales, while Pituiglomerulus capricornicus is sister genus to Chrysocystis fragilis in the Chrysocystaceae (Sarcinochrysidales). Using fixation by high-pressure freezing for electron microscope observations, a distinctive PT was observed in the three new genera described in this paper, as well as four genera not previously investigated: Chrysoreinhardia, Sargassococcus, Sungminbooa and Andersenia. The mechanism of PT formation is novel, being fabricated from rafts in Golgi-derived vesicles before being inserted into an established PT. Extracellular wall and/or mucilage layers assemble exterior to the PT in most pelagophytes, the materials likewise secreted by Golgi-derived vesicles, though the mechanism of secretion is novel. Secretory vesicles never fuse with the plasma membrane as in classic secretion and deposition, but rather relocate extracellularly beneath the PT and disintegrate, the contents having to pass through the PT prior to wall and/or mucilage synthesis. This study substantiates the diverse nature of pelagophytes, and provides further evidence that the PT is a sound morphological feature to define the Pelagophyceae, with all 14 of the 20 known genera studied to date by TEM possessing a PT.

Diversity and Distribution of Marine Macro Algae at Dickwella, Bathigama Algal Bed in Southern Sri Lanka

Seaweeds or marine macro algae are important factors in marine biodiversity of Sri Lanka. They are classified into three divisions as Chlorophyta (green algae), Phaeophyta (brown algae) and Rhodophyta (red algae). Irrespective of the great ecological importance and the higher potential for the economic uses, studies on marine macro algae in Sri Lanka is scanty. The current research was aimed at studying the diversity and distribution of marine macro algae at Dickwella, Bathigama algal bed in Southern coast Sri Lanka. The algal bed of 75 m×5 m were studied using 12 quadrates (0.5 m×0.5 m) distributed systematically with 15 m gap along the four line transects which were located parallel to the coast and with 5 m gap between them. The identification of macro algal species was done according to the standard guidelines and abundance was assessed following the Braun-Blanuet cover abundance scale. According to the results, twenty five species were found including nine Rhodophytes, twelve Chlorophyta, and four Pheaophyta. There was greater species richness in intertidal zone and high species diversity was found in upper intertidal zone of beach rock. Ulva fasciata and Caulerpa recemosa were the highest abundance species. Sargassum sp. was very high on intertidal zone covering a large area of the algal bed. Lower intertidal zone of algal platform had a lower species diversity as well as the lower species abundance. C. recemosa and crustose coralinealgae were the dominant in the study area. Halimeda sp. were recorded in the sand portion of the intertidal pools. The results suggests that the continuous survey with monthly intervals to study the seasonal variations of the algal flora and introduce rules and regulations are important to conserve algal diversity in Sri Lankan coastal belt.
 Keywords: Bathigama algal bed, Sri Lanka, Diversity, Marine macro algae

A new species of anthothelid octocoral (Cnidaria, Alcyonacea) discovered on an algal reef of Taiwan.

A molecular phylogenetic analysis of 132 octocoral species reveals a close relationship between specimens collected from the intertidal pools of the Datan Algal Reef, Taoyuan, Taiwan, and Erythropodiumcaribaeorum (Duchassaing & Michelotti, 1860), but the two species have distinct morphological features. On the basis of morphological differences in polyps and sclerites, we identify and describe a new Erythropodium species: E.taoyuanensissp. nov. The distinct identifying features of E.taoyuanensissp. nov. include the upright contractile polyps from thin encrusting membranes and abundant 6-radiate sclerites. Using an integrative approach, we present the findings of morphological comparisons and molecular phylogenetic analyses to demonstrate that E.taoyuanensissp. nov. is distinct from other Erythropodium species. Our study contributes to the knowledge of octocoral biodiversity in marginal habitats.

Pools of resilience

We describe an extreme habitat for scleractinian corals in intertidal rock pools of southeastern Australia. The pools host a small but hardy subset of coral species despite experiencing conditions beyond those documented for corals anywhere in Australia. Understanding mechanisms behind this may improve insights into climate change adaptation in corals.

Robustness of temperate versus tropical food webs: comparing species trait-based sequential deletions

Loss of species can unleash a cascade of secondary extinctions that cause dramatic changes in the structure and dynamics of food webs. The consequences for the food web depend on the traits of the species that are lost; thus, it is crucial to identify species’ traits associated with secondary extinction risk. Another important issue is to determine where the most vulnerable ecosystems are located. In this study, we aimed to compare the robustness of temperate versus tropical ecosystems to species loss. A total of 34 intertidal rock pools were analysed from a temperate and a tropical region (17 pools in each). Binary food web networks were assembled for each pool depicting who eats whom. Eighteen topological network properties were estimated to compare temperate and tropical webs. Robustness, a measure of network tolerance to species extinction, was assessed. Species loss was simulated in silico using sequential deletion protocols aimed at species that were (1) most connected, (2) least connected, (3) most abundant, and had the largest (4) body mass (mean weight) and (5) size (mean length). Tropical food webs exhibited higher robustness than temperate food webs. Both temperate and tropical food webs were less robust when the removal was directed at the most-connected species, confirming that highly connected species are particularly important in food webs. This study revealed, for the first time, that the positive relationship previously found between robustness and connectance is only confirmed for temperate webs, highlighting the need for more tropical case-studies in general data sets.

Mismatch between shape changes, early growth, and condition for a temperate reef fish from an oceanic island

Settlement is a key process in the life history of marine fish, when shape and ecological changes occur during the transition from a pelagic larva to a benthic juvenile. We studied the covariation of shape changes, condition, and pre- and post-settlement growth of settlers (17–30 mm) of the wrasse, Pseudolabrus gayi, from the Robinson Crusoe island, south-eastern Pacific. Specimens were collected during late March 2018 from four locations at 20 m depth and from a large, natural intertidal pool. The morphospace and the allometry were characterised by landmark-based geometric morphometrics, size and growth were estimated using sagittae otolith microstructure analysis, and condition was determined using the Fulton index. The settler’s phenotype varied from a robust shape with ventrally oriented mouth opening, to slender specimens with frontally oriented mouth, with similar body morphospace among sites. The mean pelagic larval duration was 44.8 ± 4.6 days, settling at 19 ± 2 mm SL. The mean post-settlement growth rate was low (0.09 mm day−1), showing low static allometry (3%). Differences among locations occurred in terms of settler’s condition and growth prior and after settlement, suggesting effects of the microhabitat and potential predators. Therefore, the variability in the settler’s morphospace was decoupled of pre- and post-settlement growth and condition during the transition from pelagic to benthic habitat. Finally, this study highlights the dynamic nature of the settlement–transition period for a temperate reef fish in a period when phenotype variations in body shape and early life-history traits vary asynchronously.

Tracking a “Prehistoric Pompeii” , Rhinoland and Crocodilia: New Discoveries And Interpretations Of Ipolytarnóc (N Hungary) Lower Miocene Track Site

The transnational Novohrad-Nograd Geopark situated in Northern Hungary and Southern Slovakia has several important Neogene fossil sites developed for geotourism. One of them is the lower Miocene paleontological locality complex at Ipolytarnoc , which has been well known since the middle of the 19th century. The site is the main geotouristic gateway to the geopark, where high-tech interpretation resources explain the geological background and fossil resources to visitors, like the rich shark-tooth-bearing intertidal sandstone, the terrestrial sandstone and rhyolite tuff containing a petrified forest and leaves, and the great number of animal tracks in a relatively small area. Since 2015, the authors have identified several thousand footprints and body impressions, including new fish, amphibian, reptile, bird, and mammal ichnotaxa, among others. Re-interpretation of the paleohabitats identifies interfingering terrestrial (Rhinoland) and intertidal pool (Crocodilia) landscapes. Similar track assemblages of similar age indicate intensive tectonic uplift and fluviatile-lacustrine sediment accumulations in the Western, Central and Eastern Paratethys forced by Neogene African plate movements.

At the Edges of Unmeeting: Geometries of Sea and Land in Marianne Moore’s Seascapes

AbstractThis article theorizes the edge between the land and the sea in Marianne Moore’s poetry and in Jeff Wall’s photograph “The Flooded Grave.” For these artists, the edge is constituted as an array of fluctuating temporal rhythms created by living organisms and dynamic abiotic elements, such as changing tides and the rocky or sandy substrates that make up the geological formation of the coastline. The edge appears in a number of Moore’s poems, including “The Fish,” which depicts the intertidal zone populated by injured “crow-blue mussel-shells,” “ink- / bespattered jelly fish,” and sea-stars, which resemble “pink / rice-grains.” Wall’s photograph, in turn, portrays a transposition between an aquatic and a terrestrial environment by placing an intertidal pool filled with star fish and sea anemones into the rectangular space of a grave. This article reads such moments as experiments in the textured edges of displacement. In these instances of intertidal encounter, organisms find themselves in unlikely configurations of space and time as a consequence of geophysical and ecological redistributions associated with effects of climate change.

Intertidal Polychaetes as Indicators of Pollution Resulting from Anthropogenic Activities along the Okpoka Creek, Upper Bonny Estuary, Nigeria

The Okpoka river and the Amadi creek are tributaries of the upper bonny estuary. The study is aimed at identifying the intertidal polychaete species and their abundance in these areas, and using them as indicators of pollution. Three stations were sampled for 6 months on a monthly basis at Marine Base, Abuloma and Kalio-Ama. Results gotten from Water samples collected from intertidal pools are as follows; Biochemical Oxygen Demand(BOD) (3.31-4.0)mg/l,, Dissolved Oxygen(DO) (6.40-6.44)mg/l, Conductivity (22.69-25.89)ms/cm, Total Dissolved Solids(TDS) (11.34-12.96)PPT, Salinity (13.65-15.74)PPT, pH (6.58-6.86), Turbidity (45.41-75.11)NTU, Temperature (28.30-31.82)oC, Nitrate(NO3) (2.11-4.10)mg/l, Phosphate(PO4) (0.82-1.10)mg/l, Sulphate(SO4,) (7.51-15.38)mg/l and Total Petroleum Hydrocarbon(TPH) (0.03-0.13)mg/l. The values of NO3, pH, Conductivity, TDS, Salinity showed significance in location and time. PO4 was significantly different between locations (p<0.05). BOD, SO4, TPH and DO showed significance in time while Turbidity and Temperature showed no significance. Results gotten from Analysis done for sediment nutrient parameters such as NO3(15.50-26.40)mg/l and PO4(13.32-15.90)mg/l showed significant variations in location and time, TPH(21.93-34.71)mg/l showed significant variations in location and SO4(15.85-19.71)mg/l had no significance in both location and time. Polychaete family and species identified in this study include: Eunicidae (Lumbrinereis aciculata, Lumbrinereis californiensis), Syllidae (Syllis ramosa, Syllis gracillis, Syllis armata), Capitellidae (Capitella Capitata), Spionidae, Glyceridae and Nereidae (Nereis diversicolor). The dry season witnessed a high number of polychaetes, about 65% of the total number of polychaetes collected from all study locations, while the wet season experienced a low count of about 34% of the total polychaetes collected from all sampled stations. The presence of lumbrinereis sp indicates negatively a poor benthic condition which was present with 25.8% abundance. The high abundance of Nereis sp with 45% abundance indicates heavy metals pollution and the presence of Glycera sp with 4% percentage abundance and Syllid sp with 15.6% percentage abundance indicates unpolluted conditions. In conclusion the abundance and diversity of polychaetes in Marine base, Abuloma and Kalio Ama were generally poor. This is evident by the poor abundance, composition and diversity of benthic fauna of the study area.

Scyphozoa Pelagia noctiluca (Forsskal, 1775): blooming on the coast of Gujarat, India and its predation by Anemonia viridis (Forsskal, 1775)

The jellyfish bloom, i.e. the aggregation of Pelagia noctiluca, which occurred in January 2016 along the Shivrajpur coast facing the Arabian Sea, is reported. The jellyfish population was studied based on the Pelagia noctiluca individuals that were stranded in low tide pools and those that were washed ashore. Transects were laid to collect data on the jellyfish density. The oceanographic and physicochemical parameters at the time of bloom were studied. The probability of correlation between the time of bloom and the movement of P. noctiluca was considered. Additionally, mating and predation on the species were documented. We assume that the jellyfish bloom might have drifted to this coast due to the landlocked characteristics of the Arabian Sea and northward movements of sea currents. So far, jellyfish has been known to be the dietary preference of several vertebrate predators. Here, we report an interesting event of Anemonia viridis feeding on Pelagia noctiluca during their blooms in several intertidal pools on the coast.