Foraminiferal evidence for a pre‐middle eocene age of the chatham rise,New Zealand

Several sediment samples collected from the crest and slope of the Chatham Rise, and from the Chatham Islands, to the east of New Zealand, contain Globigerina linaperta‐Globorotalia increbescens foraminiferal faunas of upper Middle and middle Upper Eocene age. The foraminiferal faunas from the Chatham Islands, which include Rectuvigerina, Latibolivina, Dyocibicides, Discorbinella, Patellina, and Wadella, indicate shallow‐water palaeodepths, probably equivalent to the outer shelf (50–150 m). A faunal assemblage from near the crest of the rise is likewise indicative of shallow water, although distinct differences in the benthonic foraminiferal ifauna suggest slightly deeper‐water biofacies than the Eocene of the Chatham Islands. In contrast, a fauna of similar age from 1,100 m on the southern slope of the Chatham Rise contains a much deeper‐water benthonic foraminiferal assemblage including Osangularia, Vulvulina, Stilostomella, hispidocostate Uvigerina, and smooth‐shelled Bulimina, indicative of lower middle bathyal depths (1,500–2,500 m).

The nature and distribution of the assemblages, together with previous work by Norris (1964) and Cullen (1965), indicates that the Chatham Rise has been a significant structure since at least the Middle Eocene, with some uplift occurring since then.     

Culture,demography and biogeography of sponge science: From past conferences to strategic research?

Perceived changes in the culture of sponge science and sponge conferences served as motivation for an evaluation of the sponge science community and research, over time and at present. Observed changes included a decrease in proceedings publications on sponge fossils and freshwater sponges, sponges from temperate environments, review papers and data syntheses, frequency of aquarium studies, and number of species investigated per publication. Publications on recent sponges, hexactinellids, calcareans, marine, Indo‐Pacific and warm‐water sponges increased, as well as the number of authors per publication and the proportion of field studies. Studies at the level of specimens and ultrastructure were gradually replaced by molecular approaches, but studies at the community level remained stable. The five sub‐disciplines morphology/taxonomy, phylogeny/evolution, physiology, ecology and faunistics also retained about equal proportions over time. Conference publications related to taxonomy, phylogeny and biodiversity prevailed, whereas those on management and conservation were rare, possibly because studies on sponge recovery, survival and mortality were also scarce. The community of sponge scientists has grown and become more diverse over time, presently representing 72 nations. The gender distribution evened out since the first sponge conference and presently favours women at early and men at late career stages. Although stated research interests are generally dominated by physiology and ecology, taxonomy and evolution are favoured after retirement. Sponge science has become more dynamic, but maybe also more competitive and less inclusive. We now face the dual challenge of safeguarding against the loss of some sub‐disciplines, and fostering the collaborative, helpful culture characteristic of sponge science.     

Feeding habits of the ommastrephid squid Nototodarus sloanii on the Chatham Rise,New Zealand

The diet of the squid Nototodarus sloanii was determined from examination of stomach contents of 388 specimens of 14.3–41.0 cm dorsal mantle length sampled at depths of 211–760 m on the Chatham Rise, New Zealand. Prey items were predominantly mesopelagic fishes, with some crustaceans and cephalopods. The most important prey species identified was Maurolicus australis, followed by Lampanyctodes hectoris, and unidentified squids (Teuthoidea). Multivariate analyses using distance‐based linear models, non‐parametric multi‐dimensional scaling, analysis of similarities, and similarity percentages, indicated crustaceans were more important in the diet of smaller squid (83–480 g), the fish component of the diet was dominated by L. hectoris on the east Chatham Rise and M. australis on the west Chatham Rise, and there may be a difference in diet with sex, with crustaceans and cephalopods more important for females. The results indicated that N. sloanii, similar to other ommastrephid squids, foraged primarily in the mesopelagic layers.     

The Subtropical Convergence east of New Zealand

Hydrographic data from the region of the Subtropical Convergence east of New Zealand between 177°E and 179°E show that in spring the convergence occurs near the Chatham Rise. North of the Chatham Rise the structure is fairly regular with isolines of temperature and salinity sloping upwards towards the south. To the south of the Chatham Rise the structure is more complex with an apparent intrusion of Subtropical Water into the Sub‐antarctic Water below depths of about 150 m.     

The antipodes fracture zone,a major structure of the south‐west pacific

The steep Antipodes Scarp, along the eastern boundary of the Campbell Plateau south‐east of New Zealand, is attributed to dextral tear‐faulting within a NE‐SW belt, the Antipodes Fracture Zone, which also truncates the eastern end of the Chatham Rise. A complementary zone of sinistral movement, the Waipounamu Fracture, separates the Campbell Plateau and Chatham Rise from mainland New Zealand.

The origin of these fracture zones is linked with that of the parallel Alpine Fault of South Island, and is related to a phase of NE‐SW crustal compression that dominated the New Zealand region during the Mesozoic era. It is suggested that this compression resulted from the north‐eastward “drift” of the Australian craton and the simultaneous elevation of the Darwin Rise in the central Pacific.     

Diet and dietary variation of New Zealand hoki Macruronus novaezelandiae

The diet of hoki was determined from examination of stomach contents of 1992 fish of 26–112 cm total length (TL) sampled at depths of 209–904m on Chatham Rise, New Zealand, from summer research trawl surveys and seasonal commercial fishing trawls, during 2004–2008. Prey was predominantly euphausiids, mesopelagic fishes and natant decapods. Multivariate analyses using distance-based linear models, non-parametric multi-dimensional scaling and similarity percentages indicated that the best predictors of diet variability were the position of the fish in relation to the subtropical front (STF), fish size and longitude. Pasiphaeids were more important to the north of the STF, and sternoptychid fishes and euphausiids more important in the STF convergence area. Euphausiids and sternoptychid fishes were important for smaller hoki (26–55 cm TL), myctophid fishes and natant decapods for larger hoki, and macrourids for the largest hoki (>84 cm TL). The longitudinal effect was characterised by pasiphaeids, euphausiids and sternoptychids to the west, and myctophids in the centre of Chatham Rise. Feeding activity was analysed using generalised additive models, and was found to vary with time of day, sample source (research or commercial), longitude, hoki size and depth. The variability in diet suggested hoki forage opportunistically within their preferred habitat and biological limits.     

Role of scavenging in a synaphobranchid eel (Diastobranchus capensis,Barnard, 1923), from northeastern Chatham Rise,New Zealand

Scavengers perform an important role in deep-sea ecosystems, recycling carrion. However, scavenged material can be difficult to discern from predation. The synaphobranchid eel Diastobranchus capensis Barnard, 1923, is common bycatch in deep-water fisheries for orange roughy (Hoplostethus atlanticus Collett, 1889) in New Zealand waters. Despite anecdotal reports of scavenging in D. capensis, their ecology and feeding are little known. Scavenged material was estimated to be approximately 39 per cent (by weight) of the diet of D. capensis from northeastern Chatham Rise, New Zealand, from water depths of 1062–1196 m. Scavenged material was defined as fragmentary food items from animals and plants either not normally available to the eel, or from animals larger than the eel consuming them (e.g., fish heads and tails, spent squid spermatophores, beaks and tentacle crowns, and seaweed). D. capensis were primarily piscivorous, with the diet supplemented by squid, natant decapods and mysids. The weight or number of food items did not increase with the size of the eel, nor was there any major ontogenetic shift in the composition of the diet. D. capensis probably plays an important role in mid-slope communities, recycling carrion.     

Sea surface ichthyoplankton off southeastern New Zealand,summer 1977–78

Plankton samples from the Chatham Rise, Pukaki Rise, and Campbell Plateau provided information on the young stages of a number of poorly known New Zealand fish species, and on the presence of a large spawning area of barracouta, Thyrsites atun, over the Mernoo Bank, The Chatham Rise was more important as a spawning area than the areas further south.     

The morphology and behaviour of larvae of some intertidal sponges

The morphology, swimming behaviour, settlement preferences and behaviour of five species of Demospongiae are described. The sponges, Haliclona sp., Microciona coccinea, Ophlitaspongia seriata, Mycale macilenta, and Halichondria moorei, are all common in the intertidal region in the north of New Zealand. The view is put forward that larval behaviour must be interpreted in terms of the known ecological situation of the adult sponge.     

Recruitment of Demosponges (Porifera,Demospongiae) in Rocky and Coral Reef Habitats of Santa Marta,Colombian Caribbean*

Abstract. Recruitment of demosponges (Porifera, Demospongiae) was monitored bimonthly for one year (March 1987 – March 1988) on acrylic plates, and compared to cover of adults, in six rocky and coral reef habitats at Santa Marta, Colombian Caribbean, an area subjected to seasonal, upwelling-outwelling regimes. According to suggestive but not significant trends, recruitment rates are more positively influenced by the total sponge cover near groups of plates than by cover at a larger (habitat) scale; recruit mortality is lower where recruitment is higher. These findings are in agreement with a model of higher settlement (probably due to short-distance dispersal) and lower postsettlement mortality within a few meters of adult sponges. Recruitment varied seasonally, being relatively high from May to November-December during the rainy, outwelling season, when seawater temperature was warmer, water turbidity higher, and benthic algal density lower; it was very low from January to April during the dry, upwelling season.     

Fisheries for orange roughy (Hoplostethus atlanticus) on seamounts in New Zealand

Major commercial fisheries for orange roughy (Hoplostethus atlanticus) occur on seamount features, which are widely distributed throughout the New Zealand region. When the fishery developed in the late 1970s to early 1980s, it occurred mainly on flat bottom, but over time has become more focused on seamounts. In the 1995–1996 fishing year, it is estimated that about 70 % of the catch of orange roughy within the New Zealand EEZ was taken from seamounts. Seamounts on the Chatham Rise have been fished for over ten years. Examination of commercial catch and effort data show strong declines in catch rates over time, and a pattern of serial depletion of seamount populations, with the fishery moving progressively eastwards to unfished seamounts along the southern margins of the Rise. Catch rates on seamounts in other regions of New Zealand have also generally shown a similar pattern of rapid decline. There is growing concern over the impact of trawling on seamounts, and the effects this can have on the benthic habitat and fauna, and the long-term sustainability of associated commercial fisheries.     

Hydrozoa (Cnidaria) symbiotic with Porifera: a review

Many hydroids are symbiotic with other organisms. Sponges, because of their complex canal system and their filter‐feeding activity inducing a continuous water flow, are used by numerous species as either exclusive or facultative substrata. The associated hydroid fauna thriving on or inside sponges shows a wide range of relationships with their hosts. Hydroids may be simply epibiotic on sponges, their stolons running on the host surface. Alternatively, the stolons may grow inside the sponge body, the polyps emerging from the sponge surface, having also the possibility of retraction inside the sponge tissue. Finally, stolons and branches may develop deeply inside the sponge body, producing a skeletal network for sponge growth. This paper reviews the described relationships of hydrozoans symbiotic with sponges and reports new observations.     

Genetic and meristic variation in black and smooth oreos in the New Zealand exclusive economic zone

Meristic and genetic methods were used to determine the stock relationships of black Allocytus niger (James, Inada & Nakamura, 1988) and smooth oreo Pseudocyttus maculatus (Gilchrist, 1906) in the New Zealand Exclusive Economic Zone (EEZ). Samples were collected from four management areas—OEO 1 (south‐west), OEO 3A (Chatham Rise west), OEO 4 (Chatham Rise east), and OEO 6 (subantarctic) during the 1998 October‐December spawning period. Lateral line scale counts and pyloric caeca counts revealed differences between black oreo samples from OEO 6 and the other three OEO management areas. Lateral line scale counts in smooth oreo showed no significant differences between areas. Genetic analyses of four non‐coding regions of nuclear DNA and mitochondrial (mt) DNA haplotypes in black oreo showed no significant differentiation among the four management areas. Likewise for smooth oreo, genetic analyses of five non‐coding regions of nuclear DNA and mtDNA haplotypes showed no overall regional differentiation, although there was weak evidence at one locus for a difference between OEO 3A and OEO 6. The data do not reject the null hypothesis of a single genetic stock in New Zealand waters, and are typical of marine species with long pelagic juvenile stages.     

Oceanic circulation in the head of the Hikurangi trench,east coast,New Zealand

The geostrophic flow and direct current measurements in the inflow of the Southland Current into the Hikurangi Trench east of New Zealand confirm the geostrophic circulation pattern previously found. The northwards inflow of the Southland Current at the latitude of the Chatham Rise (44°S) is estimated at 1.7 × 10⁶ m³.s^‐1, which compares favourably with that of 1.2 × 10⁶ m³.s^‐1 calculated previously off Kaikoura.     

Quantifying the relative intensity of fishing on New Zealand seamounts

New Zealand seamounts support major fisheries for several deepwater fish species, including orange roughy (Hoplostethus atlanticus) and smooth oreo (Pseudocyttus maculatus). Although a high proportion of features in the depth range 500–1000 m have been fished, very little is known about the ecological impacts of bottom trawling on seamounts. The potential impact is likely to be influenced by the spatial extent and frequency of fishing. A new index is presented to assess the relative intensity of trawling on New Zealand seamounts. The fishing effects index (FEI) incorporates information on the density of fishing on the seamount as a proportion of the seabed area and also on tow direction. Detailed fisheries data from more than 250 000 tows were examined to calculate FEI for New Zealand seamounts. The most intensively fished seamounts were on the south Chatham Rise, an area characterised by a large number of relatively small features which were fished serially for orange roughy in the 1980s and 1990s. Other seamounts with high FEI were on the north Chatham Rise, Challenger Plateau, and off the east coast of the North Island. A range of sensitivity analyses indicated that the general rankings of seamounts were relatively robust to the choice of arbitrary thresholds used to assign tows to seamounts.     

New records of xenophyophores from the upper slope around New Zealand

Recent cruises to the Chatham Rise and to the Challenger Plateau have provided new material of 3 species of xenophyophores: Reticulam‐mina labyrinthica Tendal, 1972; Syringammina fragillissima Brady, 1883; and S. tasmanensis Lewis, 1966. These records confirm the occurrence of S. fragillissima in New Zealand waters, indicate a wide distribution of S. tasmanensis, and amend our knowledge of species variation and depth range of the New Zealand xenophyophores.     

The Sponge Population of the Cabrera Archipelago (Balearic Islands): Characteristics, Distribution, and Abundance of the Most Representative Species

Abstract. The abundance, distribution, and species richness of the littoral sponges (0–55 m) from the Cabrera Archipelago (Balearic Islands) were studied along light gradients from the surface to the sea bottom and from cave mouths to their inner parts. A total of 98 species (11 Calcarea and 87 Demospongiae ) were recorded, 8 of which are new records for the Spanish coast.
Cluster and correspondence analyses enabled the identification of a sciophilous sponge group including three subgroups: sponges found only in semi-dark cave habitats, a subgroup common to the coralligenous, precoralligenous, and semi-dark cave biocoenoses, and a third subgroup exclusive to the coralligenous biocoenosis. A small number of photophilic species and other species having a wide bathymetric distribution made up another separate group. No species clusters for the different semi-sciophilous (either fleshy or carbonate) or photophilic seaweed communities were discernible. The number of sponge species was negatively correlated with the irradiance level.     

Calculated sea area of the New Zealand 200 nautical mile Exclusive Economic Zone

A calculation of the area of the New Zealand 200 nautical mile Exclusive Economic Zone is presented with definitions, cartographic methods, and calculations based on areas of quadrilaterals of the earth's surface of 1° extent in latitude and longitude. An area of 1 181 487 square international nautical miles (4 053 049 km²), ± 0.377%, includes enclaves adjacent to the Chatham Rise and the Pukaki Rise retained for assessments related to fisheries research programmes.     

Glauconitic coating on a gastropod,Fusitriton laudanum,from the Chatham rise,New Zealand (note)

Superficial coatings of glauconite grains have been observed on the gastropod mollusc, Fusitriton laudanum, from the Reserve Bank, Chatham Rise. The glauconite predates the shell on which it accretes and is incorporated on to the shell surface by agglutination of sand‐size material by mucus secreted by epizoic anemones.