Spatial and temporal variation of meiofauna community structure in soft-sediment pools around Moreton Bay, Australia

2015 ◽  
Vol 63 (3) ◽  
pp. 204
Author(s):  
Craig A. Chargulaf ◽  
Ian R. Tibbetts

In eastern Australia, small ephemeral soft-sediment pools are common on sheltered sand- and mudflats, and are occupied by the juveniles of fishes of economic and ecological importance. To address the question of whether these pools are merely refugia or whether they constitute a hitherto unrecognised nursery feeding habitat for small obligate meiobenthivorous fishes, we surveyed the meiofaunal communities of ephemeral soft-sediment pools within three intertidal shores of Moreton Bay, Australia. Highest mean meiofaunal abundances occurred at Godwin Beach and differed significantly throughout the year. Nematodes and copepods were the most abundant taxa while all other taxa contributed to <10% of the total meiofaunal abundance. Pool characteristics (i.e. volume and surface area) did not correlate with the abundance of benthic faunal assemblages. Overall, ephemeral soft-sediment pools of Moreton Bay support meiofaunal communities that are likely to provide prey resources for juvenile and small fish that use them as nurseries at low tide.

2015 ◽  
Vol 72 (8) ◽  
pp. 2398-2408 ◽  
Author(s):  
Lotfi Rabaoui ◽  
Yu-Jia Lin ◽  
Mohammad A. Qurban ◽  
Rommel H. Maneja ◽  
Javier Franco ◽  
...  

Abstract Because of the increasing oil industry development in the Arabian Gulf, hundreds of oil and gas facilities have been installed in both offshore and inshore areas during the last few decades. However, no studies have been conducted till now on the influence of these platforms on the structure and composition of marine faunal assemblages. The present work addresses this issue to propose environmental management measures connected to the utilization of fishery resources. Offshore and inshore surveys were carried out along the Saudi Gulf waters using trawl and beach-seine nets, respectively. Data relative to only fish (offshore) and fish and invertebrates (inshore) were collected concurrently with several factors: density of oil and gas facilities (offshore), distance to the nearest coastal platform (inshore), oceanographic variables, and habitat characteristics. Results of offshore surveys indicated higher fish density—both total and of fishery resources—in locations with a higher number of oil and gas facilities within a 5 km radius, whereas biomass density was not significantly different. Hence, oil and gas facilities seem to serve as nursery areas for small fish. For inshore communities, more species and diversity were found in stations closer to coastal oil and gas facilities. In addition, among the five coastal embayments sampled, those with more oil and gas facilities had more species. The findings of the present work support the hypothesis of a positive net ecological role of oil and gas platforms of the Saudi Arabian Gulf, with the implication that this effect could be extended to improve the sustainability of important fishery resources.


2017 ◽  
Vol 98 (5) ◽  
pp. 1097-1107 ◽  
Author(s):  
Robin E. Sarabia ◽  
Michael R. Heithaus ◽  
Jeremy J. Kiszka

Bottlenose dolphins (Tursiops truncatus) are abundant in many coastal ecosystems, including the coastal Everglades. Understanding spatial and temporal variation in their abundance and group sizes is important for estimating their potential ecological importance and predicting how environmental changes (e.g. ecosystem restoration) might impact their populations. From August 2010 to June 2012, we completed a total of 67 belt transects covering a total of 2650 linear km and an area of 1232 km2. Dolphin densities varied spatially and temporally. The highest densities of dolphins were found in coastal oceans and inland bays and were lowest in rivers. Use of rivers, however, increased during the dry season while densities in other habitats remained similar across seasons. Dolphins appeared to prefer portions of bays close to mangrove-covered islands over open waters. A resighting rate of 63.6% of individuals across the 2-year study suggests that at least a portion of the population is probably resident within study regions over long time periods. The largest groups (mean 6.28, range 1–31) were found in open waters and bays despite apparently low predation pressure. Indeed, shark bite scars – likely the result of unsuccessful predation attempts – were conclusively observed on only 1% of individuals. Although further studies are warranted, the high densities of dolphins suggest that they are an important upper trophic level predator in the coastal Everglades, but their ecological importance probably varies in space and time.


2018 ◽  
Vol 69 (2) ◽  
pp. 277 ◽  
Author(s):  
R. A. Kenyon ◽  
R. C. Babcock ◽  
Q. Dell ◽  
E. Lawrence ◽  
C. Moeseneder ◽  
...  

The multiple-use Moreton Bay Marine Park in eastern Australia was rezoned in 2009, increasing the total no-take marine national park (MNP) from 0.5 to 16%. In the present study we measured trends in the human use of no-take areas using observed vessel position and categorisation during on-water and aerial surveys before and after rezoning. Measured changes in spatial patterns of fishing showed that the effects of rezoning on most fishing activity was minimal. After rezoning, the proportion of recreational fishing declined from 6.3 to 2.6% of the footprint in the new MNPs. The proportion of commercial fishing declined from 25 to 1%, although the amount of commercial fishing was low. There was an overall increase in fishing activity on Moreton Bay. Low recreational fisher displacement suggests that the expansion of the MNP area did not have a high social cost. However, most of the no-take zones were areas not previously subject to high recreational fishing pressure. If a significant proportion of the no-take zones were placed in areas of low ecological production, the biodiversity conservation impact achieved by the rezoning of Moreton Bay may have been less than the 16% increase in no-take areas would imply.


ZooKeys ◽  
2018 ◽  
Vol 783 ◽  
pp. 17-36
Author(s):  
Julian Uribe-Palomino ◽  
Sarah Pausina ◽  
Lisa-Ann Gershwin

Two new species of small hydromedusae were found during routine monitoring in coastal waters of eastern Australia and are here described. The first,MelicertissaantrichardsoniUribe-Palomino &amp; Gershwin,sp. n., from Moreton Bay, Queensland, is placed in its genus because of its possession of both cordyli and eight-fold symmetry. It differs from its congeners in two conspicuous features: firstly, having small, oval split gonads located adjacent to the base of the stomach, and secondly, in its extremely small size at maturity (2 mm bell diameter, compared to the next smallest species at 7 mm). Moreover, it possesses a unique combination of other characters. This species appears to be endemic to Moreton Bay. The second new species,ParaloveniayongalensisGershwin &amp; Uribe-Palomino,sp. n., from the Great Barrier Reef, Queensland, is placed in its genus because of its two opposite normal tentacles and two opposite marginal clusters of cirri. It differs from its congeners primarily in a more rounded body than the others; the shape, length, and position of its short spindle-shaped, distal gonads; possession of subumbrellar nematocyst clusters; and possession of statocysts. These discoveries bring the total number ofMelicertissaspecies to eight and the total number ofParaloveniaspecies to three. The discovery of these two micromedusae underscores the need for further examination of the often-ignored minute and/or gelatinous fauna.


1986 ◽  
Vol 3 ◽  
pp. 2-3
Author(s):  
Jay Hall

1986 has been a very good year for archaeology in Queensland. As the following pages testify, fundamental research is being undertaken throughout the length and breadth of the state. Furthermore it is being carried out by researchers who hail from not only Queensland but institutions throughout Australia. Perhaps the most significant discovery reported this year was the site of Wallen Wallen Creek on North Stradbroke Island, Moreton Bay (see R. Neal and E. Stock, Nature 1986:618-621). While excavating a recent surface midden for salvage purposes, Rob Neal, a Ph.D candidate at Queensland University, discovered a deep (2.5m) deposit within a coastal dune which yielded a continuous human occupation sequence. Collaboration with geomorphologist Errol Stock from Griffith University established that two soil units were formed after the dune was laid down and that associated cultural material is relatively undisturbed. C14 dating revealed an internally consistent series of determinations which stretch to over 22,000 B.P. Present results indicate a dramatic increase in occupation intensity (as measured by discard rate) in the late Holocene (esp. after ca. 2,000 B.P.), a pattern which fits well with results from other research in this area (eg. Hall Robins QAR, Volume 1) as well as other parts of eastern Australia. This discovery has provided the Pleistocene-Holocene chronological framework that has been sought for the Moreton Region for several years now. Future analysis of Wallen Wallen Creek material promises to add much to our notions of cultural change in this and adjacent areas.


PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3308 ◽  
Author(s):  
Ryota Nakajima ◽  
Elvis V. Rimachi ◽  
Edinaldo N. Santos-Silva ◽  
Laura S.F. Calixto ◽  
Rosseval G. Leite ◽  
...  

The boundary zone between two different hydrological regimes is often a biologically enriched environment with distinct planktonic communities. In the center of the Amazon River basin, muddy white water of the Amazon River meets with black water of the Negro River, creating a conspicuous visible boundary spanning over 10 km along the Amazon River. Here, we tested the hypothesis that the confluence boundary between the white and black water rivers concentrates prey and is used as a feeding habitat for consumers by investigating the density, biomass and distribution of mesozooplankton and ichthyoplankton communities across the two rivers during the rainy season. Our results show that mean mesozooplankton density (2,730 inds. m−3) and biomass (4.8 mg m−3) were higher in the black-water river compared to the white-water river (959 inds. m−3; 2.4 mg m−3); however an exceptionally high mesozooplankton density was not observed in the confluence boundary. Nonetheless we found the highest density of ichthyoplankton in the confluence boundary (9.7 inds. m−3), being up to 9-fold higher than in adjacent rivers. The confluence between white and black waters is sandwiched by both environments with low (white water) and high (black water) zooplankton concentrations and by both environments with low (white water) and high (black water) predation pressures for fish larvae, and may function as a boundary layer that offers benefits of both high prey concentrations and low predation risk. This forms a plausible explanation for the high density of ichthyoplankton in the confluence zone of black and white water rivers.


2018 ◽  
Author(s):  
James Douglass ◽  
Richard Paperno ◽  
Eric A. Reyier ◽  
Anson H. Hines

A growing number of examples indicate that large predators can alter seagrass ecosystem structure and processes via top-down trophic interactions. However, the nature and strength of those interactions varies with biogeographic context, emphasizing the need for region-specific investigations. We investigated spatial and temporal variation in predatory fish and seagrass communities across a Marine Protected Area (MPA) boundary in the Banana River Lagoon, Florida (USA), assessing trophic roles of intermediate consumers, and performing a large-consumer exclusion experiment in the MPA. Large, predatory fishes were most abundant within the MPA, while some mid-sized fishes were more abundant outside it. Small, seagrass-resident fishes, epifaunal invertebrates, and macrophytes also differed across the MPA boundary, but varied more among individual sites and seasonally. We cannot conclusively attribute these patterns to MPA status because we lack data from prior to MPA establishment and lack study replication at the level of MPA. Nevertheless, other patterns among our data are consistent with hypothesized mechanisms of top-down control. E.g., inverse seasonal patterns in the abundance of organisms at adjacent trophic levels, coupled with stable C and N isotope and gut contents data, suggest top-down control of crustacean grazers by seasonal recruitment of small fishes. Large-consumer exclosures in the MPA increased the abundance of mid-sized predatory and omnivorous fishes, but had few impacts on lower trophic levels. Results suggest that large-scale variation in large, predatory fish abundance in this system does not strongly affect seagrass-resident fish, invertebrate, and algal communities, which appear to be driven more by habitat structure and seasonal variation in small fish abundance.


1981 ◽  
Vol 32 (1) ◽  
pp. 133 ◽  
Author(s):  
SA Halse

Five saline lakes near Marchagee. with salinities ranging from 10-71‰, were sampled every two months between March and September 1979. The lakes contained faunal assemblages of 6-13 invertebrate species; only two species were common to all lakes. Fish (Pseudogobius olorum) were found in one salt lake. Austrochiltonia subtenuis was recorded at a salinity of 71‰ twice the salinity it was previously thought to tolerate. Pseudogobius olorum was collected at a salinity of 55‰ and is the second species of fish to be collected from highly saline Australian lakes. Mytilocypris mytiloides was collected at a total dissolved solids concentration of 45‰ a much higher level of salinity than it tolerates in eastern Australia. Necterosoma pensillatus was found at a salinity of 10.5‰ the lowest yet recorded for the species.


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