Flying south: Foraging locations of the Hutton's shearwater (Puffinus huttoni) revealed by Time-Depth Recorders and GPS tracking.

The Hutton's shearwater Puffinus huttoni is an endangered seabird endemic to Kaikoura, New Zealand, but the spatial and temporal aspects of its at-sea foraging behavior are not well known.To identify foraging areas and estimate trip durations, we deployed Global Positioning Systems (GPS) devices and Time-Depth Recorders (TDR) on 26 adult Hutton's shearwaters during the chick-rearing period in 2017 and 2018.We found Hutton's shearwaters traveled much further from their breeding grounds at Kaikoura than previously considered, with most individuals foraging in coastal and oceanic areas 125-365 km south and near Banks Peninsula. Trip durations varied from 1 to 15 days (mean = 5 days), and total track lengths varied from 264 to 2,157 km (mean = 1092.9 km).Although some diving occurred in near-shore waters near the breeding colony, most foraging was concentrated in four regions south of Kaikoura. Dive durations averaged 23.2 s (range 8.1 to 71.3 s) and dive depths averaged 7.1 m (range 1.5 to 30 m). Foraging locations had higher chlorophyll a levels and shallower water depths than nonforaging locations. Birds did not feed at night, but tended to raft in areas with deeper water than foraging locations.Mapping the spatial and temporal distribution of Hutton's shearwaters at sea will be fundamental to their conservation, as it can reveal potential areas of overlap with fisheries and other industrial users of the marine environment.

Effects of waterborne cadmium on energy metabolism in the tropical sea cucumber, Stichopus horrens, and a comparison of tissue-specific cadmium accumulation with the temperate sea cucumber Australostichopus mollis.

The sea cucumber Stichopus horrens is an important component of near-shore ecosystems, and in the Kingdom of Tonga it also comprises an important commercial and subsistence fishery. To assess the sensitivity of this species to the toxic trace metal cadmium (Cd), adult S. horrens were exposed for 96h to an environmental (15µgL-1) or effect (765µgL-1) concentration of waterborne Cd. The respiratory tree and intestine accumulated higher concentrations of Cd than the muscle and body wall, but there were no effects of Cd on tissue ions (sodium, potassium, magnesium, calcium). For comparison, Cd accumulation was also examined in the Australasian sea cucumber Australostichopus mollis. This species displayed a similar pattern of tissue-specific accumulation to S. horrens, but exhibited lower tissue Cd burdens, likely a consequence of lower experimental temperature. Effects on gonad ion content were also seen in this species. At the highest Cd exposure concentration, S. horrens showed impaired ammonia excretion rates and an increased molar oxygen:nitrogen ratio (O:N), indicative of a decreased reliance on protein metabolism. Overall, this study suggests that S. horrens is relatively tolerant of Cd exposure, but raises concerns regarding the subsistence fishery practice of consuming the viscera of this species.

Factors influencing the en route survivorship and post-voyage growth of a common ship biofouling organism, Bugula neritina.

The likelihood that viable non-indigenous biofouling species will survive a voyage on a vessel is influenced by a range of factors, including the speed, duration, and route of the voyage and the amount of time the vessel spends in port. In this study, a land-based dynamic flow device was used to test the effect of recruit age, vessel speed and voyage duration on the survivorship and growth of the bryozoan Bugula neritina. In the experiment, one-week-old recruits had a higher likelihood (100%) of surviving voyages than older (one-month-old, 90%) or younger (one-day-old, 79%) recruits, but survival was not influenced by vessel speed (6 and 18 knots) or voyage duration (two and eight days). The results suggest that the non-indigenous species B. neritina can be effectively transferred at a range of ages but one-week-old recruits are more likely to survive the translocation process and survive in the recipient environment.

Phylogenetic affinities of the Fregetta storm-petrels are not black and white.

The Fregetta storm-petrels generally are regarded to comprise two species: black-bellied storm-petrels F. tropica (monotypic) breed at Antarctic and sub-Antarctic islands (46-63°S), and white-bellied storm-petrels F. grallaria breed at south temperate islands (28-37°S), with four recognized subspecies. Confusion surrounds the status of birds at Gough Island (40°S), central South Atlantic, which have been attributed usually to a white-bellied form of black-bellied storm-petrel F. t. melanoleuca. We use cytochrome b and nuclear ß-fibrinogen gene sequences to show that F. t. melanoleuca are present during the breeding season at Gough and islands in the nearby Tristan da Cunha archipelago (37°S), exhibiting limited divergence from F. t. tropica. We also show that there is greater diversity among F. grallaria populations, with eastern South Pacific F. g. segethi and F. g. titan differing by c. 0.011, and both differing from western South Pacific nominate F. g. grallaria by c. 0.059. The Tristan archipelago supports a population of F. grallaria closely allied to the nominate form, as well as a distinct form identified as F. g. leucogaster. Further research is needed to assess how F. grallaria and F. tropica segregate in sympatry at Tristan and Gough, and why this is the only location where both species have white-bellies.

Hybrid-Lambda: simulation of multiple merger and Kingman gene genealogies in species networks and species trees.

BACKGROUND: There has been increasing interest in coalescent models which admit multiple mergers of ancestral lineages; and to model hybridization and coalescence simultaneously. RESULTS: Hybrid-Lambda is a software package that simulates gene genealogies under multiple merger and Kingman's coalescent processes within species networks or species trees. Hybrid-Lambda allows different coalescent processes to be specified for different populations, and allows for time to be converted between generations and coalescent units, by specifying a population size for each population. In addition, Hybrid-Lambda can generate simulated datasets, assuming the infinitely many sites mutation model, and compute the F ST statistic. As an illustration, we apply Hybrid-Lambda to infer the time of subdivision of certain marine invertebrates under different coalescent processes. CONCLUSIONS: Hybrid-Lambda makes it possible to investigate biogeographic concordance among high fecundity species exhibiting skewed offspring distribution.

Using temporal sampling to improve attribution of source populations for invasive species.

Numerous studies have applied genetic tools to the identification of source populations and transport pathways for invasive species. However, there are many gaps in the knowledge obtained from such studies because comprehensive and meaningful spatial sampling to meet these goals is difficult to achieve. Sampling populations as they arrive at the border should fill the gaps in source population identification, but such an advance has not yet been achieved with genetic data. Here we use previously acquired genetic data to assign new incursions as they invade populations within New Zealand ports and marinas. We also investigated allelelic frequency change in these recently established populations over a two-year period, and assessed the effect of temporal genetic sampling on our ability to assign new incursions to their population of source. We observed shifts in the allele frequencies among populations, as well as the complete loss of some alleles and the addition of alleles novel to New Zealand, within these recently established populations. There was no significant level of genetic differentiation observed in our samples between years, and the use of these temporal data did alter the assignment probability of new incursions. Our study further suggests that new incursions can add genetic variation to the population in a single introduction event as the founders themselves are often more genetically diverse than theory initially predicted.

When rediscovery is not enough: taxonomic uncertainty hinders conservation of a critically endangered bird.

In 2003, birds similar to the extinct New Zealand storm-petrel Oceanites maorianus were observed in Hauraki Gulf NZ, raising the possibility of rediscovery after 150 years. O. maorianus has and continues to be surrounded by taxonomic uncertainty, being variously described as a distinct genus, a distinct species, or merely a plumage variant. This uncertainty has hindered conservation planning and funding for the species. Here we examine the taxonomic identity of the rediscovered birds and museum specimens using phylogenetic analysis of mitochondrial (1143 bp cytochrome b) and nuclear (890 bp ß-fibrinogen) genes. Using cytochrome b sequence amplified from the 150+ year old specimens, we found that the extant and museum O. maorianus were the same taxon (0.01 genetic distance), with both differing from all other storm-petrel taxa. Using both genes, we examined the phylogenetic affinities of O. maorianus to the Oceanitinae and Hydrobatinae storm-petrels finding that O. maorianus was more closely aligned to Fregetta (0.08-0.09) than Oceanites (0.11-0.12), thereby confirming its status as a distinct taxon, not a plumage variant of O. oceanicus. Our analysis verifies that the previously presumed extinct New Zealand storm-petrel has been rediscovered and can now be assigned a conservation priority commensurate with its critically endangered status.

Global phylogeography of the widely introduced North West Pacific ascidian Styela clava.

The solitary ascidian Styela clava Herdman, 1882 is considered to be native to Japan, Korea, northern China and the Russian Federation in the NW Pacific, but it has spread globally over the last 80 years and is now established as an introduced species on the east and west coasts of North America, Europe, Australia and New Zealand. In eastern Canada it reaches sufficient density to be a serious pest to aquaculture concerns. We sequenced a fragment of the cytochrome oxidase subunit I mitochondrial gene (COI) from a total of 554 individuals to examine the genetic relationships of 20 S. clava populations sampled throughout the introduced and native ranges, in order to investigate invasive population characteristics. The data presented here show a moderate level of genetic diversity throughout the northern hemisphere. The southern hemisphere (particularly New Zealand) displays a greater amount of haplotype and nucleotide diversity in comparison. This species, like many other invasive species, shows a range of genetic diversities among introduced populations independent of the age of incursion. The successful establishment of this species appears to be associated with multiple incursions in many locations, while other locations appear to have experienced rapid expansion from a potentially small population with reduced genetic diversity. These contrasting patterns create difficulties when attempting to manage and mitigate a species that continues to spread among ports and marinas around the world.

Comparative phylogeography of coastal limpets across a marine disjunction in New Zealand.

Cook Strait, which separates the North and South Island of New Zealand, has been a transient, but re-occurring feature of the New Zealand land mass throughout the Pleistocene, maintaining its current width and depth for the past 5000 years. Historic land fragmentation coupled with the complex hydrography of the Greater Cook Strait region has created both biogeographic and phylogeographic disjunctions between the North and South Island in several marine species. Here we use mitochondrial cytochrome b DNA sequences of three endemic intertidal limpets, Cellana ornata, Cellana radians and Cellana flava to assess intraspecific phylogeographic patterns across Cook Strait and to look for interspecific concordance of ecological and evolutionary processes among closely related taxa. We sequenced 328-359 bp in 85-321 individuals from 8-31 populations spanning the biogeographic range of the three species. Intraspecific phylogeographic analyses show moderate to strong genetic discontinuity among North and South Island populations due to allopatric fragmentation. This pattern was broadly concordant across the three species and the observed divergence among this group of intertidal limpets (0.3-2.0%) is similar to that of previously studied subtidal organisms. For each species, divergence time calculations suggest contemporary North and South Island lineages diverged from their respective most recent common ancestor approximately 200 000 to 300 000 years before present (bp), significantly earlier than previous estimates in other coastal marine taxa that arose from a miscalculation of divergence time.