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Site‐occupancy modelling is widely used in ecology for understanding species distribution, habitat‐use and community changes but its application is still limited in paleoecology, where incomplete detection is also routine. Here, we make extensive expansions to an earlier multispecies occupancy model used to estimate the dynamics of relative species abundance in fossil communities. These expansions include incorporating counts of individuals at sites, explicitly allowing for the inclusion of specimens assignable to genus – but not species‐level, a situation common in paleontology, and modelling regional presence/absence. We provide simulations to check the performance of this new model, as well as simulations to quantify the benefits of using individual count data versus subsample occupancy data, and model estimates versus face‐value (raw) estimates, respectively. We also provide an empirical case study using occupancy data from a community of marine benthic colonial animals preserved in the Pleistocene of New Zealand. We find that the new model performs well, especially when it comes to recovering relative abundance dynamics and that it is well worth the effort to both collect individual count data and to include individuals unidentified to species‐level in the site‐occupancy modelling framework. This extended model can be widely applied in paleoecological settings and is necessary when both the average and uncertainty values of relative abundance dynamics need to be robustly estimated. [ABSTRACT FROM AUTHOR]

Macrobenthic traits, for example feeding mode, life history, morphology, are increasingly used for determining responses of macrobenthic fauna to environmental change and influences on ecosystem functioning. Yet, trait information is scarce or non-existent in several parts of the world, such as New Zealand. This deficit makes collecting trait data a difficult and time-consuming task, limiting its potential use in trait-based assessments. Here, we present the New Zealand Trait Database (NZTD) for marine benthic invertebrates, the first comprehensive assessment of macrobenthic traits in New Zealand. The NZTD provides trait information for more than 700 macrobenthic taxa, categorised by 18 traits and 77 trait modalities. The NZTD includes five freely downloadable datasets, (1) the macrobenthic trait dataset, with outcomes from a fuzzy coding procedure, (2) the trait source information, (3) the references by taxa, (4) the full references list, and (5) the full taxa list used in the NZTD. Establishing the NZTD closes the trait knowledge gap in New Zealand and facilitates future research applying trait-based approaches to New Zealand's coastal macrofauna. [ABSTRACT FROM AUTHOR]

Understanding the responses of organisms to different environmental drivers is critical for improving ecosystem management and conservation. Estuarine ecosystems are under pressure from multiple anthropogenic stressors (e.g. increasing sediment and nutrient loads, pollution, climate change) that are affecting the functions and services these ecosystems provide. Here, we used long-term estuarine benthic invertebrate monitoring data (∼30 year time-series) to evaluate the responses of macrobenthic invertebrate communities and indicator species to climatic, oceanic, freshwater, and local environmental drivers in New Zealand estuaries. We aimed to improve our ability to predict ecosystem change and understand the effects of multiple environment drivers on benthic communities. Our analyses showed that the abundance and richness of macrobenthic fauna and four indicator taxa (bivalves known to have differing tolerances to sediment mud content: Austrovenus stutchburyi , Macomona liliana , Theora lubrica , and Arthritica bifurca) responded to unique combinations of multiple environmental drivers across sites and times. Macrobenthic responses were highly mixed (i.e., positive and negative) and site-dependent. We also show that responses of macrobenthic fauna were lagged and most strongly related to climatic and oceanic drivers. The way the macrobenthos responded has implications for predicting and understanding the ecological consequences of a rapidly changing environment and how we conserve and manage coastal ecosystems. • Long-term estuarine monitoring data (∼30 yrs) was used to evaluate the responses of macrofauna to environmental drivers. • Macrofauna responded to unique combinations of multiple environmental drivers. • Macrofaunal responses to environmental drivers were idiosyncratic and site-mediated. • Macrofaunal responses were mostly related to lagged permutations of climatic and oceanic drivers. • We highlight the complexity of predicting macrofauna responses to environmental change. [ABSTRACT FROM AUTHOR]

Understanding community assembly is a key goal in community ecology. Environmental filtering influences community assembly by excluding ill‐adapted species, resulting in communities with similar functional traits. An RLQ (a four‐way ordination) analysis incorporating spatial data was run on a data set of 642 species of cheilostomes (Bryozoa) from 779 New Zealand sites, and results were compared to trends in other sessile, epibenthic taxa. This revealed environmental filtering of colony form: encrusting‐cemented taxa were predominant in shallow environments with hard substrata (<200 m), while erect‐rooted taxa characterized deeper environments with soft substrata (>200 m). Furthermore, erect taxa found in shallow environments with high current speeds were typically jointed. Polymorphism also followed environmental gradients. External ovicells (brood chambers) were more common in deeper, low‐oxygen water than immersed and internal ovicells. This may reflect the oxygen needs of the embryo or increased predation intensity in shallow environments. Bryozoans with costae tended to be found in deeper water as well, while bryozoans with calcified frontal shields were found in shallow environments with a higher concentration of CaCO3. Avicularia did not appear to be related to environmental conditions, and changes in pivot bar structure with depth likely represent a phylogenetic signal. The importance of substratum type as a strict environmental filter suggests that anchoring structures, like rootlets, may be "key innovations" for other sessile, epibenthic taxa like sponges and ascidians. [ABSTRACT FROM AUTHOR]

Abstract The aim of this study was to develop a simple methodology using foraminifera to distinguish between sediment that has been displaced downslope (as in a turbidity current) and in-situ hemipelagic sediment. These same methods will also be useful to identify seafloor foraminiferal faunas that have suffered considerable taphonomic modification (e.g., through dissolution, winnowing, mixing), which render them unsuitable as modern analogues for paleoenvironmental reconstructions. To help develop this methodology we used Late Quaternary samples from cores containing identified turbiditic sand-mud couplets that had been deposited at lower bathyal to upper abyssal depths (1400–3000 m) off the earthquake-prone east coast of New Zealand. Comparison of the proportions of the total planktic and benthic foraminiferal tests in each of three size categories (63–125 μm, 125–250 μm, >250 μm) with those in unmodified, in-situ modern bathyal faunas from off New Zealand showed an increased proportion of larger tests in the lower sandy turbidite layers and a slight increase of smaller tests in the upper muddy layers presumably as a result of winnowing processes during deposition. A regression formula was used to estimate depositional depths based on the relative abundance of planktics in the Quaternary foraminiferal faunas (>63 μm). In all but one of our core samples, these depth estimates were considerably shallower than the cores' present depth and suggested that most sediment (both sand and mud) had been transported downslope. Modern Analogue Technique (MAT) was used to estimate depths of deposition of the core samples based on a modern benthic foraminiferal dataset (>63 μm) from around New Zealand. There was no great difference between estimates based on species % and on genus %. Some MAT depth estimates were inconsistent with those from the other foraminiferal and sedimentological proxy methods that suggested turbiditic displacement. Because of the inconsistent results and the much greater work required to acquire the species census data we exclude the MAT method from our suggested methodology. Genera were lumped into groups with similar bathymetric range and the relative abundances of these groups in each core sample were used to infer sediment provenance and mixing during downslope transport. We recommend a methodology using three elements: Test size distribution, planktic percentage, and relative abundance of bathymetric groups of benthic genera. The first two require the least amount of work and can reliably identify the majority of displaced and taphonomically-modified faunas. The third requires some taxonomic skills to identify key genera but gives more information on the provenance depth and amount of mixing in displaced turbiditic sediment. Although developed using New Zealand modern and Late Quaternary foraminiferal data, we contend that these methods should be applicable for use throughout most of the Neogene in other temperate and subtropical parts of the world's oceans. Before use elsewhere, studies in the local region may be needed to test, recalibrate and tweak the modern analogue data on local test-size distribution and planktic percentage. Our study also suggests that these methods can be useful to identify seafloor foraminiferal faunas that have suffered considerable taphonomic modification (e.g., through dissolution, winnowing, mixing), which render them unsuitable as modern analogues for paleoenvironmental reconstructions. Highlights • Simple method proposed to distinguish in-situ from transported foraminiferal faunas. • Relative abundance of foraminiferal test sizes is modified by transport and dissolution. • Relative abundance of planktic foraminiferal tests aids recognition of transported faunas. • Many benthic genera can be grouped based on their live bathymetric distribution. • Relative abundance of benthic bathymetric groups of genera aids recognition of provenance. [ABSTRACT FROM AUTHOR]

Understanding and predicting change in deep-sea benthic ecosystem function remains a major challenge. Here, we conducted analyses combining data on the abundance and biomass of benthic fauna and sediment community oxygen consumption (SCOC) on New Zealand’s continental margin to estimate and compare the contributions of meio-, macro-, and megafauna to total benthic metabolism and identify potential links with environmental factors and trawling intensity. We focussed on two regions in close proximity-the high surface primary productivity Chatham Rise and low surface productivity Challenger Plateau. Mean megafauna biomass was twenty times greater on Chatham Rise than Challenger Plateau, likely reflecting differences in food supply between the two regions; this contrast in megafaunal biomass was mainly due to differences in mean body weight rather than abundance. Meio- and macrofauna made similar contributions to SCOC and together accounted for 12% of benthic metabolism on average. In contrast, the estimated contribution of megafauna never exceeded 1.5%. Significant positive correlations between faunal respiration and food availability indicate a link between food supply and benthic community function. Our analyses also show that fauna made a greater contribution to SCOC in conditions of high food availability, and that microorganisms (i.e., the proportion of SCOC not accounted for by the fauna) tended to be more dominant at sites with low food availability. These findings provide support for the concept that large organisms are more strongly affected by a reduction in food resources than small organisms, which in turn underlies one of the most widely described patterns in the deep-sea benthos, i.e., the reduction in organism body size with depth. Because metabolism in deep-sea sediments is typically dominated by microorganisms and small fauna, the absence of a relationship between bottom trawling intensity and the respiration of benthic fauna in the present study may be explained by benthic communities shifting towards smaller body size following physical disturbance. Future studies of deep-sea benthic ecosystem function will need to quantify the indirect influence of fauna on microbial metabolism through activities such as feeding and bioturbation in order to better understand the total contribution of benthic fauna to benthic processes. [ABSTRACT FROM AUTHOR]

To investigate regional drivers of spatial patterns in macro- and meio-faunal community structure (abundance, biomass and taxonomic diversity) and ecosystem function (sediment community oxygen consumption [SCOC]), we sampled two regions in close proximity on New Zealand's continental margin—the Chatham Rise and the Challenger Plateau. Sites (n= 15) were selected in water depths ranging from 266–1212 m to generate a gradient in sedimentary properties and, in particular, surface pelagic productivity. Both macro- and meio-fauna abundance and biomass was 2–3.5 times higher on the Chatham Rise than on the Challenger Plateau, reflecting regional differences in pelagic primary production. We also found significant inter- and intra-regional differences in macro-fauna taxonomic diversity with two distinctive site groupings in each region. Univariate and multivariate measures of macro-fauna community attributes were most strongly correlated with sediment photosynthetic pigment (explaining 24%–59% of the variation). Sediment pigment content was as equally important in explaining meio-fauna community structure (36%–7%). Unlike community structure, SCOC was most strongly correlated with depth (44%), most likely reflecting temperature effects on benthic metabolism. Our results highlight the importance of a benthic labile food supply in structuring infaunal communities on continental margins and emphasise a tight coupling between pelagic and benthic habitats. [ABSTRACT FROM PUBLISHER]

We developed habitat suitability curves (HSC) using generalised additive models (GAMs) for nine benthic macroinvertebrate taxa from a small New Zealand river for hydraulic-habitat modelling assessments of instream flow requirements. We included interaction terms between the primary variables (water depth, velocity, substrate) when significant, to address a longstanding criticism of univariate HSC. To date, only large-river univariate HSC have been available and these have been used in hydraulic-habitat applications on small rivers, despite doubt over the transferability of HSC between rivers of different size and type. We tested the outcome on the predicted abundance–flow relationship of applying the small-river habitat suitability GAMs versus large-river GAMs for two taxa on the same small river. We found the effects of flow allocation were overestimated by the large-river GAMs relative to the small-river GAMs. Further research to develop general HSC for categories of river size and type is needed to better inform hydraulic-habitat modelling applications. [ABSTRACT FROM PUBLISHER]

Abstract: The food and feeding relationships of mid-slope slickheads in New Zealand waters are little known compared with those from the northern hemisphere. This study examines the feeding relationships of three common slickhead species from approximately 1000m on Chatham Rise, New Zealand: Alepocephalus antipodianus (Parrot, 1948), A. australis (Barnard, 1923), and Xenodermichthys copei (Gill, 1884). The Alepocephalus species were predominantly benthopelagic feeders with a small benthic component to their diets. Alepocephalus australis fed on pelagic tunicates, notably Pyrosoma atlanticum Péron, 1804. Alepocephalus antipodianus fed on fish and pelagic tunicates, and also crustaceans. Xenodermichthys copei fed primarily on crustaceans. Considerable material was recovered from the intestines of all three species, and much of it was identifiable and only partially digested, including the remains of pelagic tunicates. There was little dietary overlap between the stomach contents of the three slickhead species indicating a degree of niche partitioning. Intestinal contents differed from stomach contents in weight, but not in number of items for all three species. The composition of stomach and intestinal contents differed for A. australis, but not for A. antipodianus or X. copei, which suggests that intestinal contents could be potentially useful in lieu of stomach content. There was a high level of overlap between the intestinal contents of A. antipodianus and A. australis, suggesting a possible closer dietary relationship between these two species than that indicated by stomach contents alone. Despite limitations in sample size and spatial and temporal coverage, the results from this study indicate that the three slickhead species could play an important role in the structuring of the demersal community at mid-slope depths on northeastern Chatham Rise. [Copyright &y& Elsevier]

Abstract: Recent surveys of periphyton in Lake Tikitapu revealed widespread benthic mats dominated by cyanobacteria. All mats tested positive for the cyanobacterial toxin nodularin-R. The New Zealand native freshwater crayfish or kōura (Paranephrops planifrons) are benthic-dwelling, opportunistic omnivores that are common in Lake Tikitapu. Benthic mats constitute a potential food source for this species. In this study an in-lake feeding experiment with isotopically labeled 13C benthic mats confirmed they were consumed by kōura. Consumption was variable amongst individuals, suggesting the benthic mats are an optional rather than primary food source. Nine kōura were also tested using liquid chromatography–mass spectrometry to determine if nodularin-R bioaccumulated in the hepatopancreas and tail tissue. The hepatopancreas of all kōura were positive for nodularin-R (9.7–225.3μgkg−1 ww) and nodularin-R was detected in low concentrations in the tail tissue of two individuals (0.5–0.7μgkg−1 ww). The detection of nodularin-R in kōura is the first in a freshwater organism in a freshwater system, and the first to show the accumulation of nodularin-R from freshwater benthic cyanobacterial mats. Benthic mats may need to be considered as a potential source of cyanotoxins in future freshwater food-web studies. [Copyright &y& Elsevier]

Sponges play a key role in Antarctic marine benthic community structure and dynamics and are often a dominant component of many Southern Ocean benthic communities. Understanding the drivers of sponge distribution in Antarctica enables us to understand many of general benthic biodiversity patterns in the region. The sponges of the Antarctic and neighbouring oceanographic regions were assessed for species richness and biogeographic patterns using over 8,800 distribution records. Species-rich regions include the Antarctic Peninsula, South Shetland Islands, South Georgia, Eastern Weddell Sea, Kerguelen Plateau, Falkland Islands and north New Zealand. Sampling intensity varied greatly within the study area, with sampling hotspots found at the Antarctic Peninsula, South Georgia, north New Zealand and Tierra del Fuego, with limited sampling in the Bellingshausen and Amundsen seas in the Southern Ocean. In contrast to previous studies we found that eurybathy and circumpolar distributions are important but not dominant characteristics in Antarctic sponges. Overall Antarctic sponge species endemism is ∼43%, with a higher level for the class Hexactinellida (68%). Endemism levels are lower than previous estimates, but still indicate the importance of the Polar Front in isolating the Southern Ocean fauna. Nineteen distinct sponge distribution patterns were found, ranging from regional endemics to cosmopolitan species. A single, distinct Antarctic demosponge fauna is found to encompass all areas within the Polar Front, and the sub-Antarctic regions of the Kerguelen Plateau and Macquarie Island. Biogeographical analyses indicate stronger faunal links between Antarctica and South America, with little evidence of links between Antarctica and South Africa, Southern Australia or New Zealand. We conclude that the biogeographic and species distribution patterns observed are largely driven by the Antarctic Circumpolar Current and the timing of past continent connectivity. [ABSTRACT FROM AUTHOR]

Management decisions aimed at protecting biodiversity ideally should be based on biological information, but for remote and logistically difficult sites, such as are found at high latitudes, these data may be lacking. During March 2009, surveys were completed of the nearshore rocky reef communities around the Bounty and Antipodes Islands, in New Zealand's subantarctic region. Previously considered to support the same habitat types (which used physical variables as surrogates for biological communities), analysis of photoquadrats taken at both island groups showed that the rocky reef communities were significantly different, both in terms of their species composition and in terms of their potential ecological function. While Antipodes Island supported fairly typical subantarctic shallow subtidal marine communities dominated by nongeniculate coralline algae, the rocky reefs at the Bounty Islands were dominated by filter- and suspension-feeding invertebrates, in particular encrusting sponges, barnacles and mussels. The mobile invertebrate fauna associated with these communities were also significantly different between the two island groups. Contrasting geology, oceanographic conditions and nutrient input from seabird and pinniped colonies may all contribute to the observed nearshore community structures at the Bounty and Antipodes Islands. Our research provides a baseline for assessing change in the subantarctic region and highlights the importance of using biological community data where available, to inform conservation management decisions. [ABSTRACT FROM AUTHOR]

The article presents a study which aims to determine the life histories and life-cycle strategies of some invertebrates in intermittent streams in Hawke's Bay, New Zealand. The study was conducted from March 2005 to May 2007 in three different sites and used samples of various benthic macroinvertebrates including mayflies, caddisflies, and Potamopyrgus antipodarum snail. Results show that intermittent sites has more taxa, plurivoltine life cycles, and asexual reproduction than perennial sites.

Sandy coastal sediments in similar wave-exposure conditions in southeastern New Zealand supported different macrofaunal communities in an area with steeply sloped bathymetry compared with an adjacent area with a shallower slope and, therefore, a more wave-dissipating profile. Assemblages were sampled in autumn and spring along three shore-normal transects (6-30 m water depths) in two areas separated by a small headland. There was no sediment texture stratification in surficial sediments and no seasonal variability in sediment texture. Macrofaunal abundance and taxon richness were higher in both areas in spring. Taxon richness generally increased with depth in both communities. Abundance increased with depth at the more reflective site but decreased with depth at the more dissipative site until a possible autecological point was reached, whereafter both abundance and richness continued to increase with depth and community composition merged into a typical shelf community. This merge point supports the notion of a Wave Exclusion Hypothesis (WEH), a shallow subtidal analogue to the Swash Exclusion Hypothesis (SEH) developed for sandy beach processes, where turbulence and sediment instability selectively exclude macroinvertebrates. Macrofaunal communities in the more reflective area were probably constrained by abiotic factors as suggested by morphological traits of dominant taxa. Communities have largely persisted since the 1960s and 1980s. Variability within such a small spatial scale suggests that coastal management decisions should consider the special nature of nearshore environments as a distinct marine habitat where sediment instability may shape communities through different processes than those present in sheltered inlets or deeper shelf environments. [ABSTRACT FROM AUTHOR]

The effects of habitat loss on local species richness depend on the characteristics of the endangered system (including its total species pool and the distribution of species among the habitats). The present study focuses on the species-poor southern Baltic marine benthic biota. Macrobenthic samples were collected in three habitats: (1) soft bottom covered with vegetation; (2) stony reefs; (3) unvegetated sands. Fourty one percent of 54 observed macrozoobenthic species were habitat specific, while 30% occurred in all three habitats. There were no significant differences in total species richness among the three habitats. The accumulation curves plotted for subsets of data with selected habitats excluded lay below the curve plotted for the whole dataset, but only in one case the 95% confidence intervals of the subset curve did not overlap with those plotted for the whole dataset. The exclusion of samples from selected habitats produced a species richness drop ranging from 9 to 13%. The present study showed that habitat loss in a species-poor area with a relatively large ratio of generalist species cannot produce local species richness declines similar to those predicted for diverse marine systems. However, it must be emphasized that in species-poor systems, the loss of ecological function accompanying habitat loss could be disproportionally higher than that predicted based on decreases in species richness, as some functions are performed by a single species. [ABSTRACT FROM AUTHOR]

Alfaro, A. C. 2010. Effects of mangrove removal on benthic communities and sediment characteristics at Mangawhai Harbour, northern New Zealand. – ICES Journal of Marine Science, 67: 1087–1104.The spread of mangroves at many locations in temperate northern New Zealand provides a stark contrast to the well-documented trend in mangrove forest decline recorded through the tropics and subtropics. To explore this difference, improved understanding is needed of New Zealand's mangrove ecosystems and how they respond to anthropogenic disturbance. The effect of mangrove removal on the community ecology of mangrove stands and adjacent habitats was investigated within Mangawhai Estuary, northern New Zealand, between March 2004 and September 2006. The vegetation, benthic macrofauna, and sediments were sampled within habitats (marshgrass, mangrove stands, pneumatophore zones, sandflats, and channels) at a treatment site (mangroves removed) and two undisturbed sites, before and after mangrove-removal activities. Mature mangrove habitats had less total abundance and fewer taxa than all the other habitats sampled and were dominated by pulmonate snails (Amphibola crenata) and mud crabs (Helice crassa). Whereas faunal composition varied seasonally as a result of life-history dynamics, temporal changes could be attributed to mangrove-removal activities. Mangrove eradication was followed by immediate changes in the sediment from a muddy to sandier environment, which favoured an overall increase in the abundance of crabs, snails, and bivalves. However, unexpected topographic catchment reconfigurations in late 2005 may have caused a subsequent increase in the delivery of silt and organic content to the study area and an overall decrease in faunal density in March and September 2006. The study provides direct evidence of the effect of mangroves on sediment and benthic faunal characteristics and the importance of catchment-derived imports to estuarine ecosystems. [ABSTRACT FROM PUBLISHER]

Because the nature, tempo and trajectories of biological changes that follow the cessation of trawling are unknown for seamounts, it is unclear whether closing them to trawling will lead to a recovery of the fauna and, if so, over what time scales. This paper reports on a ‘test of recovery’ from repeated towed camera surveys on three seamounts off New Zealand in 2001 and 2006 (5 years apart) and three off Australia in 1997 and 2006 (10 years apart). In each region, seamounts where trawling had ceased were compared to adjacent seamounts where trawling was still active, and to seamounts that had never been trawled. If recovery signals existed, the likelihood of detecting them was high because the seamounts were relatively small and topographically simple, and because quantitative survey methods were employed. Multivariate patterns showed no change in the megafaunal assemblage consistent with recovery over a 5–10 year timeframe on seamounts where trawling had ceased. Results based on the number of species and diversity were equivocal, with some cases of increase and decrease on seamounts where trawling had ceased. A few individual taxa were found at significantly higher abundance in the later surveys where trawling had occurred. We suggest this may have resulted from their resistance to the direct impacts of trawling (two chrysogorgid corals and solitary scleractinians), or from protection in natural refuges inaccessible to trawls (unstalked crinoids, two chrysogorgid corals, gorgonians, and urchins). Alternatively, these taxa may represent the earliest stages of seamount recolonisation. They have potential to be dominant for long periods because the pre-trawling composition of benthic assemblages on seamounts includes taxa that grow slowly and/or have an association with ‘thickets’ of a single keystone stony coral ( Solenosmilia variabilis) that has generated biogenic habitat over millennia. Resilience of seamount ecosystems dominated by corals is low compared to most other marine systems subject to disturbance by bottom trawling because there are no alternative habitats of the same value for supporting associated species, and because trawling typically removes coral habitat from large areas of individual seamounts. Management to conserve seamount ecosystems needs to account for changing oceanographic conditions (ocean acidification), as well as the direct impacts of human activities such as bottom trawling. Networks of spatial closures that include intact habitats over a range of depths, especially <1500 m, and on clusters and isolated seamounts, may be effective by maintaining the resilience of seamount benthic communities. [ABSTRACT FROM AUTHOR]

The article presents a study that examined how incorporating restricted colonist dispersal decreases the range of spatial and temporal rates of disturbance under which benthic communities can persist, using model parameters representative of a New Zealand marine biogenic-structured community. Researchers used a spatially explicit patch dynamic model to show the interaction of the disturbance regime and colonization processes in regulating community dynamics and landscape structure in marine benthic systems. They concluded that the scale of the disturbance regime and dispersal processes are fundamentally coupled, and knowing the scales of both processes is important in predicting change in the structure and diversity of benthic communities threatened by cumulative change.

Mat-forming benthic cyanobacteria are widespread throughout New Zealand rivers, and their ingestion has been linked to animal poisonings. In this study, potentially toxic benthic cyanobacterial proliferations were collected from 21 rivers and lakes throughout New Zealand. Each environmental sample was screened for anatoxins using liquid chromatography-MS (LC-MS). Thirty-six cyanobacterial strains were isolated and cultured from these samples. A polyphasic approach was used to identify each isolate; this included genotypic analyses [16S rRNA gene sequences and intergenic spacer (ITS)] and morphological characterization. Each culture was analysed for anatoxins using LC-MS and screened for microcystin production potential using targeted PCR. The morphospecies Phormidium autumnale was found to be the dominant cyanobacterium in mat samples. Polyphasic analyses revealed multiple slight morphological variants within the P. autumnale clade and highlighted the difficulties in identifying Oscillatoriaceae. Only one morphospecies (comprising the two strains CYN52 and CYN53) of P. autumnale was found to produce anatoxins. These strains formed their own clade based on partial 16S rRNA gene sequences. These data indicate that benthic P. autumnale mats are composed of multiple morphospecies and toxin production is dependent on the presence of toxin-producing genotypes. Further cyanobacteria are also characterized, including Phormidium murrayi, which was identified for the first time outside of Antarctica. [ABSTRACT FROM AUTHOR]

The article discusses research done on feeding habits and niche separation among several deep-sea chimaeroid fishes found in Chatham Rise, New Zealand, including Hydrolagus (H.) novaezealandiae, H. bemisi and Harriotta (H.) raleighana. The study procedure included the examination of the digestive tract contents of the fishes, which were fed on benthic infauna and epifauna. Results revealed that the diets of H. novaezealandiae, H. bemisi and H. raleighana were characterized by crabs and sea urchins, by crabs and polychaetes, and by polychaetes and molluscs, respectively.

Historically described as cosmopolitan but rare, the benthic diatom Didymosphenia geminata is now considered a nuisance, bloom-forming and invasive species. In New Zealand, D. geminata was first recorded in 2004 in the lower Waiau River. By winter 2008 it had been identified in 26 major catchments. To investigate invasion success of D. geminata in relation to succession and biomass accumulation of native periphyton communities, we conducted a two-factorial field experiment. Seven successional stages of a native periphyton community (substrate exposure time: 0-49 days) were exposed to two D. geminata propagule concentrations (low and high) for 25 days. D. geminata propagule concentration and successional stage of the native periphyton community significantly affected the invasion success of D. geminata. While D. geminata invasion was low on all substrates that had been exposed to the low D. geminata propagule concentration, there was a unimodal relationship between invasion success and substrate exposure time at the high propagule concentration. D. geminata abundance was low on uncolonised substrates, increased when the native communities were 1- or 2-week-old, and low when the age of the native communities was 4 or more weeks. These results imply that D. geminata is a late successional species that needs some existing structure to anchor to a substrate. Although late successional stages of the native periphyton community displayed partial resistance to D. geminata invasion, trying to keep D. geminata abundances as low as possible appears to be the only way to manage this species at this time. [ABSTRACT FROM AUTHOR]

1. Blooms of the benthic, stalked diatom Didymosphenia geminata were first observed in New Zealand in 2004. Since then, D. geminata has spread to numerous catchments in the South Island and is also spreading in its native range. The species is a rare example of an invasive alga in lotic systems. 2. Ecosystem effects may be expected as D. geminata attains unusually high biomass in rivers. We examined data from three independent studies in three South Island, New Zealand, rivers for evidence of effects on periphyton biomass and benthic invertebrate communities. 3. The combined results confirmed that the presence of D. geminata was associated with greatly increased periphyton biomass and, in most cases, increased invertebrate densities. We also recorded shifts in community composition, dominated by increased densities of Oligochaeta. Chironomidae, Cladocera and Nematoda also generally increased in density with D. geminata. Significant increases or declines in other invertebrate taxa were inconsistent among rivers. 4. In all three studies, increased spatial invertebrate community homogeneity was associated with high D. geminata biomass at the within-river scale. However, no declines in taxon richness or diversity were detected. 5. Although ecosystem effects of D. geminata on existing periphyton biomass and invertebrate communities are measurable, no inferences can be made from the present data about effects on higher trophic levels (fish). [ABSTRACT FROM AUTHOR]

Abstract: Seamounts, knolls, pinnacles and other “seamount-like” features are prominent and widely distributed features of the New Zealand marine environment, and also the focus of important commercial fisheries and some exploratory mineral mining. There is considerable debate about the effects of such activities on the benthic habitat of deep-water seamounts. In 2001 a study was undertaken of eight seamount-features on the Chatham Rise, an area that has been heavily trawled for orange roughy since the early 1990s. Half of the study seamounts were considered unfished and the other half fished. Benthic macro-invertebrate assemblages of each seamount were sampled using epibenthic sleds, whilst the presence of habitat-forming fauna (e.g., live corals), substrate type and indications of trawling (e.g., trawl door marks) were determined using a towed underwater camera. Fisheries catch-effort data were examined to determine the amount and distribution of bottom trawling effort on the seamounts. Analyses of camera data revealed that unfished seamounts possessed a relatively large amount of stony coral habitat comprising live Solenosmilia variabilis and Madrepora oculata (predominantly on the seamount peaks) whereas fished seamounts had relatively little coral habitat. Indications of trawling were observed over six times more frequently on seabed images from fished as opposed to unfished seamounts, and appeared related to the amount of fishing effort on individual seamounts. Multivariate analyses of sled data revealed a significant difference in macro-invertebrate assemblage composition between fished and unfished seamounts. The variability observed in assemblage composition between seamounts can in part be explained by the relative fishing pressure measured by a fishing effects index. The results of the study are discussed with respect to management of seamount habitat, and the need for ongoing monitoring and research to derive conservation practices that allow for sustainable seamount fisheries. [Copyright &y& Elsevier]

Abstract: In Fiordland, New Zealand, large volumes of organic matter are deposited into the marine environment from pristine forested catchments. Analyses of δ 15N, δ 13C and δ 34S were employed to determine whether these inputs were contributing to marine food webs via assimilation by common macroinvertebrates inhabiting the inner reaches of the fjords. Terrestrially derived organic matter (TOM) had values of δ 15N, δ 13C and δ 34S that were distinct from other carbon source pools, providing sufficient power to quantify the contribution of TOM to the benthic food web. Isotopic values among macroinvertebrates varied significantly, with consistently low values of δ 15N, δ 13C and δ 34S for the abundant deposit feeders Echinocardium cordatum (Echinodermata) and Pectinaria australis (Annelida), indicating assimilation of TOM. High concentrations of bacterial fatty acid biomarkers in E. cordatum, and values of δ 13C of these biomarkers similar to TOM (−27 to −30‰) confirmed that TOM is indirectly assimilated by these sea urchins via heterotrophic bacteria. TOM was also found to enter the infaunal food web via chemoautotrophic bacteria that live symbiotically within Solemya parkinsonii (Bivalvia). Echinocardium cordatum, Pectinaria australis and S. parkinsonii comprised up to 33.5% of the biomass of the macroinfaunal community, and thus represent strong pathways for movement of organic matter from the forested catchments into the benthic food web. This demonstration of connectivity among adjacent marine and terrestrial habitats has important implications for coastal land management, and highlights the importance of intact coastal forests to marine ecosystem function. [Copyright &y& Elsevier]

Five polymorphic microsatellite loci were developed and then used to assess the population genetic structure of a commercially harvested merobenthic octopus species ( Octopus maorum) in south-east Australian and New Zealand (NZ) waters. Beak and stylet morphometrics were also used to assess population differentiation in conjunction with the genetic data. Genetic variation across all loci and all sampled populations was very high (mean number alleles = 15, mean expected heterozygosity = 0.85). Microsatellites revealed significant genetic structuring (overall FST = 0.024, p < 0.001), which did not fit an isolation-by-distance model of population differentiation. Divergence was observed between Australian and NZ populations, between South Australia and north-east Tasmania, and between two relatively proximate Tasmanian sites. South Australian and southern Tasmanian populations were genetically homogeneous, indicating a level of connectivity on a scale of 1,500 km. Morphometric data also indicated significant differences between Australian and NZ populations. The patterns of population structuring identified can be explained largely in relation to regional oceanographic features. [ABSTRACT FROM AUTHOR]

The article presents a study on the foraging and diving behavior of female sea lions or Phocarctos hookeri in New Zealand. It compares the foraging pattern of sea lions in terms of their two dive profiles which are the benthic diving and meso-pelagic diving profiles. It utilized Multitrace system to analyze the dive profile as well as determine the sea lions' dive statistics. The study found out that lactating female sea lions have a high variation level in their foraging behavior, but they tend to return in their foraging areas within their breeding seasons.

Springs are unique aquatic environments that support specific biota, including endemic species and rare species listed in Red Lists. Due to their usually small size, springs are highly sensitive to disturbance. Many of them are threatened by aquifer depletion, contamination, surface-water diversion, livestock trampling, recreation, and invasive species. The aim of this study was to assess the colonization success of the invasive New Zealand mud snail (Potamopyrgus antipodarum) in a cold spring ecosystem in southern Poland. In Europe, this species has recently been added to the top "hundred worst" alien species due to its impact on invaded ecosystems. The study was carried out in two areas of the spring ecosystem—in the springhead and the springbrook—over a four-year period. Potamopyrus antipodarum dominated the benthic macroinvertebrate communities in both areas of the spring ecosystem. Nevertheless, its abundance in the springbrook was significantly greater, and increased noticeably during subsequent years compared to that in the springhead. The populations of P. antipodarum were exclusively composed of females. Smaller-sized New Zealand mudsnails were more abundant near the spring's source than at the second site. The females at the springhead became fecund at sizes as small as 3.7 mm (the number of embryos was between 0 and 37), while at the springbrook, embryos were found in snails as small as 3.4 mm (the number of embryos was between 0 and 42). Our results suggest that the lower water temperature at the springhead may limit the population size of P. antipodarum, thus making its density too low to be able to affect the community structure of benthic macroinvertebrates, including the spring snail Bythinella cf. austriaca. [ABSTRACT FROM AUTHOR]

Abstract: Benthic soft-sediment organisms generally show strong relationships with the grain-size characteristics of the sediments they inhabit. These relationships, when characterised from field data, tend to be asymmetrical, non-linear and heteroscedastic, due to the existence of multiple other potentially important and interacting factors, some of which are inevitably unmeasured. For multivariate data, canonical analysis of principal coordinates (CAP) can be used to isolate particular gradients of interest, despite the presence of other potentially important factors. For univariate abundance data, models focusing on upper quantiles of species'' distributions can ameliorate the problem of heterogeneity induced by other variables. Here, a multivariate model of the relationship between benthic inter-tidal estuarine soft-sediment assemblages (sampled over a period of 3 years from 70 sites across the Auckland region) and the percentage of mud in the sediments was generated using CAP. To characterise changes in assemblage structure, quantile regression splines (of the 0.95 quantile) were used to model each of the twenty most abundant individual taxa along the gradient in percentage mud. This approach provided an effective instrumental quantitative predictive model of species'' turnover, while allowing for the asymmetric, non-linear animal-sediment relationships and heterogeneous scatter observed in species'' abundances along the mud gradient. [Copyright &y& Elsevier]

The article presents a study concerning the impact of hydro-electrically induced lake level fluctuations on littoral communities on benthic communities in Lake Hawea, New Zealand. It emphasizes that if lake levels are fluctuated at a rate which does not allow colonization of the newly inundated areas as levels increase, the width of the zone of littoral vegetation on the shore can reduced with potential effects on higher trophic levels such as fisheries. It cites that lake levels management in two neighboring lakes in New Zealand, including one on a lake fluctuated for hydroelectric generation and the other subject to a natural hydrologic regime, offers an opportunity to test the effects of differing disturbance regime on the benthic communities of lakes.

The article examines the differentiation between aquatic macroinvertebrate community of small headwater intermittent streams and larger mid-reach intermittent streams to nearby mid-reach perennial streams in New Zealand. It compares the fauna in the country streams to that in similar habitats outside the country. It also analyzes the flow period community to that persisting in disconnected pools after flow has ceased. The results of the study reveals that intermittent headwater streams can support diverse macroinvertebrate communities, it likely to be less diverse than those in perennial streams, and intermittent streams connected with upstream perennial reaches have more diverse aquatic communities

The article focuses on the survey regarding the first quantitative deep-benthic macrofaunal communities of New Zealand fjord in 12 basins that are divided along the two axes of the Doubtful Sound complex. It was found that there was high between sample variability of both abundance and family level alpha diversity. Despite of, the basin communities could still be separated to high, medium, and low diversity communities each having a characteristic change in family level beta diversity. The research reveals that there are distinct assemblages in the deep fjord habitats and offers quantitative base-line data for future researchers.

Meiofauna composition was investigated for six field sites, including polluted and non-polluted sites, within two regions (Auckland and Bay of Plenty) during winter (July–August 2004) in the North Island of New Zealand. Physico-chemical parameters were measured during the sampling period and meiofauna distribution and abundance were compared with these measured parameters. Analysis of meiofauna abundance indicated that foraminiferans, nematodes and ostracods were the taxa that contributed to the variability between field sites within the Auckland region. However, no clear taxa dominance was seen in the Bay of Plenty region. Comparison of meiofauna abundance and physico-chemical parameters was done using multivariate analysis (PRIMER). However, no clear relationships between the parameters were observed in any field site in either region. The Shannon-Weiner index of diversity did not show any clear differentiation between polluted and non-polluted field sites. Therefore, from the present study, the taxa or physico-chemical parameters used could not effectively characterise pollution at the investigated field sites. [Copyright &y& Elsevier]

The article examines the spatial biodiversity patterns of benthic invertebrate communities in braided channels, springs and hillslope streams in the Waimakariri River, New Zealand. The researchers have identified one hundred taxa, including several rare phreatic species. Furthermore, the springs have the highest total taxonomic richness with 81 taxa and they also have the highest diversity of unique taxa.

In marine soft sediments, large organisms are potentially important players in the nonlinear interactions that occur among animals, their food, and their chemical environment, all of which influence the contribution of benthos to ecosystem function. We investigated the consequences of removing large individuals of two functionally contrasting benthic communities on nutrient regeneration, microphyte standing stock, and macrobenthic community composition. The experiment was conducted at two adjacent sites that were physically similar but biologically different, one dominated by large deposit feeders and the other by large suspension feeders. Chemical fluxes were measured in experimental plots, and sediments were sampled to assess changes in macrofauna, sediment grain size, organic content, and microphyte standing stock. Our results demonstrate that the removal of large suspension feeders or deposit feeders influenced the flux of nitrogen and oxygen, surficial sediment characteristics, and community composition. In the deposit-feeder community, interactions between nutrient regeneration and grazing highlight important feedbacks between large macrofauna and biogeochemical processes and production by microphytes, indicating that the loss of large infauna driven by increased rates of anthropogenic disturbance may lead to functional extinction and cause shifts in community structure and ecosystem performance. [ABSTRACT FROM AUTHOR]

The article provides information on the benthic community structure and water column characteristics in the Kermadec Islands Marine Reserve (KIMR) in New Zealand. It is considered the country's largest marine reserve at 748,000 hectares and its biota is composed of a mix of warm temperate, subtropical and tropical species. Furthermore, significant differences in benthic community structure, in water column turbidity and chlorophyll concentrations are observed.

The article examines the processes of recolonization and recovery of the benthic community at the subtidal areas in Wellington Harbour, New Zealand following a bloom of the toxic dinoflagellate Karenia brevisulcata. The number of species was significantly higher at three of six stations, which the numbers of individuals increased at four of six stations. Furthermore, biological communities became more similar between stations with increasing time after the bloom.

The recovery of benthic invertebrates was investigated in the braided Tukituki and Waipawa Rivers (North Island, New Zealand) following extended channel dewatering of sites for 6, 10 or 14 weeks during summer 1997/1998. After rewatering, invertebrates rapidly colonised each denuded site and, although some invertebrates were numerically dominant at different times, 95+% of the taxa list were present after 7 days of rewatering. The number of individuals also increased over time, but significantly greater numbers were collected in reference sites and those dry for 6 weeks compared to sites dewatered for longer periods. Taxa such as Tanytarsus spp., Maoridiamesa spp. (Diptera: Chironomidae) and the riffle beetle Elmidae (Coleoptera) were abundant early, while Deleatidium spp. (Ephemeroptera: Leptophlebiidae) dominated communities later. The greater abundance of Deleatidium in sites dewatered for a short time may be because desiccation was less significant at determining taxa present at these sites, or that reference sites provided a closer source of colonists and periphyton propagules to allow a more rapid numerical recovery of this taxon. In contrast, Elmidae dominated communities at sites dewatered for longer periods because Elmidae may be more resilient to desiccation than Deleatidium. These data suggest that the duration of dewatering may regulate taxonomic composition in the short term by subjecting taxa to desiccation and/or food resource restrictions, but not in the long term because food resources recovered over time and sites with similar physicochemical conditions should have similar communities. [ABSTRACT FROM AUTHOR]

Examines the benthic food web dynamics and carbon flow in the littoral zone of Lake Coleridge in New Zealand. Use of radioactive and stable isotope techniques; Analysis of the stomach content of the fauna; Observation of a variety of epiphytic algal taxa.

Presents a study which investigated the impact of recreational boating on the benthoic organisms in Kawau Island, New Zealand. Overview of the impacts of human recreational activities on aquatic ecosystems; Materials and methods used in the study; Results.

The generation of sediment plumes by human activities, such as bottom fishing and potential deep-sea mining, poses threats to deep-sea benthic fauna. Sponges are important components of deep-sea ecosystems and can be particularly sensitive to elevated suspended sediment concentrations. In this study, we exposed the deep-sea New Zealand sponge Ecionemia novaezealandiae (Dendy, 1924) (Demospongiae: Ancorinidae) to a range of suspended sediment concentrations (SSC) (32, 78 and 475 mg l−1) and control conditions (no added sediment) continuously for two weeks. Survival was high (97%), with only one death (at the highest SSC). Half of the sponges in the 475 mg l−1 treatment showed partial necrosis by the end of the two-week exposure. Respiration rates of sponges in the sediment addition treatments decreased relative to control sponges by 27, 37 and 60%, respectively, after day 1; and by 7, 17, and 27%, respectively, after 14 days of suspended sediment exposure. At the end of the experiment, sectioning of the sponges revealed sediments deep in the tissue of all specimens, including controls, indicating previous incorporation of sediment occurred in their natural environment. Despite the high survival, the decreased respiration rates and partial necrosis with increasing SSC indicated a decline in sponge condition that could affect this species beyond the disturbance period. • Deep-sea sponges Ecionemia novaezealandiae exposed to elevated suspended sediment concentrations (SSC) for two weeks • One mortality in the highest SSC treatment; necrosis in the high SSC treatment sponges • Decreased respiration rates after one and 14 days sediment exposure • Sediment particles found internally in all sponges, including control ones [ABSTRACT FROM AUTHOR]

We compared changes in the benthos associated with discharges from a salmon farm at a low-flow location in Pelorus Sound, Aotearoa-New Zealand to the Pearson and Rosenberg model (PRM). As predicted by PRM, benthic enrichment resulted in significant increases in abundance of small, opportunistic macrofauna beneath salmon farm cages. In contrast, at reference sites we found fewer but larger, rare species. When estimates for biomass were calculated from macrofaunal size-classes, reference sites averaged 4.86 times more biomass and 4.35 times greater diversity than farm sites – results also consistent with the PRM. Farm sites favoured deposit feeders at the expense of suspension feeders and grazers. We discuss the significance of large rare species that contributed most to reference biomass estimates that appear under threat from multiple anthropogenic stressors. • Small, opportunistic macrofauna dominated beneath salmon farm sites. • Large rare species contributed more to biomass estimates at reference sites. • The farm favoured deposit feeders at the expense of suspension feeders and grazers. [ABSTRACT FROM AUTHOR]

With the intensification of urban development, agriculture, and forestry, many coastal waters are becoming enriched with nitrogen (N). Long term, excess terrestrial N accumulates in the sediment porewaters impacting benthic fauna and microphytobenthic productivity, altering the complex bio-geophysical interactions that occur on the seafloor. These interactions may influence sediment erodibility and resuspension rates on the seafloor, which have wider ecosystem consequences through changes in water column turbidity, the fluxes of organic matter and sediment porewater nutrients into the water column, and the redistribution of deposited terrestrial materials (i.e. pollutants and sediment). We conducted a field experiment to explore how bio-geophysical interactions change in the context of porewater N enrichment. The experiment enriched plots (4 m2) on an intertidal sand flat in Tauranga Harbour, New Zealand, with three concentrations of N fertiliser (0, 150 and 600 g N m−2; n = 6). After 10 weeks, we collected intact sediments from the plots, and in the laboratory, subjected these sediments to sequential increases in water flow velocity (between 0.05 and 0.4 m s−1) using annular flumes (bed area = 0.17 m−2). We calculated sediment erosion rates and thresholds, measured fluxes of NH 4 + and Chlorophyll a across the sediment-water interface and characterised the sediment properties and macrofaunal communities. We anticipated complex feedbacks to occur where porewater N enrichment would increase microphytobenthic biofilm growth, stabilising the sediments (and reducing benthic-pelagic coupling), but at the same time, N enrichment might also alter the macrofaunal community, which graze the microphytobenthos and physically mix the sediment, with a potential destabilising effect (and increase in benthic-pelagic coupling). Although our enriched treatments doubled the biomass of microphytobenthos, altered the macrofauna communities and enhanced the fluxes of Chlorophyll a and NH 4 + across the sediment-water interface, sediment erosion thresholds and rates were unaffected. Our results highlight a potential mismatch between the micro- and macro-biotic processes and the larger scale physical forces on dynamic intertidal sandflats, and this mismatch has implications for our ability to scale up small scale processes to entire ecosystems. • Estuary eutrophication can affect both top-down and bottom-up ecological processes. • We elevated sediment porewater N to test effects on microphytobenthos and grazers. • N enrichment doubled benthic microphyte biomass and altered macrofauna communities. • Enrichment effects did not alter sediment erosion threshold or rate. • Erosion of N enriched sediment released substantial nutrients and chlorophyll a. [ABSTRACT FROM AUTHOR]

An introduction is presented in which the editors discuss various reports within the issue on topics including benthic invertebrate assemblages, river basin in New Zealand and river management.

Adult common bullies, Gobiomorphus cotidianus McDowall, are small (total length = 30–120 mm), benthic fish commonly found in the littoral zones of New Zealand lakes where they are a major prey species for trout and eels. Differences in their relative abundance (CPUE) were determined between 21 shallow North Island lakes. Mean CPUE ranged from 2 to > 1000 fish net- 1 night- 1 and was inversely related to water transparency. The abundance of bullies was not reduced in lakes containing rainbow trout, Oncorhynchus mykiss (Walbaum), but was reduced in all lakes containing self-recruiting populations of eels, Anguilla spp. Mean densities of planktonic larval bullies in the limnetic zone were also inversely related to water transparency. Since low water transparency is related to increased trophic status for these lakes, the abundance of bullies is likely to be related to lake productivity, rather than turbidity. [ABSTRACT FROM AUTHOR]

In estuarine and coastal soft-sediment systems, the role that predators play in structuring communities appears to be variable. Attributes of a particular predator that influence its role in structuring the community include: the rate of prey consumption; the behaviour, morphology and mobility of the predator; and, in soft- sediment communities, sediment disturbances associated with feeding. Reviews of field experiments designed to assess the role of predators in influencing the structure and function of soft-sediment communities have concluded that many of the predators are generalists and there is usually a lack of competitive exclusion. Thus predation structures communities by many complex and indirect interactions that are often difficult to predict and generalize. Variations in the apparent strength and role of predation in structuring benthic communities may depend on a variety of ecosystem characteristics and/or aspects of study design. In this paper, I consider whether we have been conducting our experiments at the appropriate scales. Five case studies from Manukau Harbour (New Zealand) illustrate how small changes in the spatial scale can affect results, due to predator perceptions and prey mobility. The results of these studies demonstrate the need to identify scales at which predator effects are likely to be important and to fit experiments within the dynamics and heterogeneity of the system being studied. To do this, we need basic information on the natural history, behaviour and spatial and temporal variability of both predators and prey communities. We also need to be specific about scales of measurement when matching theoretical predictions to field observations/experiments. Finally, to enhance our ability to generalize from specific studies, we need to gather data that will enable us to both predict and test the importance of predation over a range of spatial and temporal scales. [ABSTRACT FROM AUTHOR]