Managing Risks from Invasive Marine Species: Is Post-Border Management Feasible?

<p>Non-indigenous marine species are a major threat to marine environments and economies globally. This thesis examines whether management of pest organisms post-border (i.e, after they have established in New Zealand) is feasible in the marine environment, using the non-indigenous Asian kelp Undaria pinnatifida as a model organism. Background information on Undaria in Chapter 2 recognises the paucity of information on Undaria's impacts. Hence, Chapter 3 investigates ecological effects from Undaria in a low shore rocky habitat. Although negligible effects were described, the uncertainty in extrapolating findings to other places and times means that the precautionary principle should be applied by managers, and 'worst-case' impacts assumed. Chapter 4 investigates mechanisms for Undaria's natural dispersal, and describes strategies based on spore release and sporophyte drift that may lead to spread over scales of metres to kilometres. This work highlights the importance of human transport vectors (especially vessels and aquaculture) in the post-border spread of Undaria at regional and national scales. Hence, a case study in Chapter 5 describes aquaculture activities that could be vectors for spread of Undaria in New Zealand, and presents criteria for identifying present and future high risk pathways. Chapters 6 and 7 describe methods to reduce the accidental transport of Undaria and other biofouling pests with aquaculture, with a focus on mussel farming. Treatments based on water blasting, air drying and freshwater immersion provide low cost options for equipment such as floats and rope. For treatment of mussel seed-stock, immersion in dilute (4%) acetic acid (the active ingredient in vinegar) is identified as a method that could eliminate Undaria and other soft-bodied fouling organisms without resulting in an unacceptable level of mussel mortality. Chapter 8 proposes a risk-based framework for setting post-border management priorities based on the feasibility, benefits and costs of risk reduction. This chapter elucidates how knowledge generated from research in Chapters 2-7 can be used in a biosecurity risk management context. It shows that effective management post-border is possible even when pest organisms become relatively well established, and that the benefits gained from even limited successes have the potential to greatly outweigh the consequences of uncontrolled invasion. However, as unwanted species become increasingly widespread, management will become increasingly focussed on the protection of specific values. Chapter 9 extends some of the ideas proposed in Chapter 8, and considers a broad postborder management framework for marine pests. A comprehensive system should consist of vector management, surveillance, and incursion response that targets particular pests or suites of functionally similar species (e.g., biofouling organisms), coupled with generic vector management approaches that aim to reduce humanmediated transport of all organisms at a national scale. New Zealand's geographic isolation and low population, hence relatively low level of vector activity, makes the management of human-mediated pathways of spread entirely feasible in many circumstances. Hence, while there are clearly many challenges in the post-border management of marine pests, this is nonetheless a realistic goal, and probably moreso in New Zealand than in any other country in the world.</p>

Managing Risks from Invasive Marine Species: Is Post-Border Management Feasible?

<p>Non-indigenous marine species are a major threat to marine environments and economies globally. This thesis examines whether management of pest organisms post-border (i.e, after they have established in New Zealand) is feasible in the marine environment, using the non-indigenous Asian kelp Undaria pinnatifida as a model organism. Background information on Undaria in Chapter 2 recognises the paucity of information on Undaria's impacts. Hence, Chapter 3 investigates ecological effects from Undaria in a low shore rocky habitat. Although negligible effects were described, the uncertainty in extrapolating findings to other places and times means that the precautionary principle should be applied by managers, and 'worst-case' impacts assumed. Chapter 4 investigates mechanisms for Undaria's natural dispersal, and describes strategies based on spore release and sporophyte drift that may lead to spread over scales of metres to kilometres. This work highlights the importance of human transport vectors (especially vessels and aquaculture) in the post-border spread of Undaria at regional and national scales. Hence, a case study in Chapter 5 describes aquaculture activities that could be vectors for spread of Undaria in New Zealand, and presents criteria for identifying present and future high risk pathways. Chapters 6 and 7 describe methods to reduce the accidental transport of Undaria and other biofouling pests with aquaculture, with a focus on mussel farming. Treatments based on water blasting, air drying and freshwater immersion provide low cost options for equipment such as floats and rope. For treatment of mussel seed-stock, immersion in dilute (4%) acetic acid (the active ingredient in vinegar) is identified as a method that could eliminate Undaria and other soft-bodied fouling organisms without resulting in an unacceptable level of mussel mortality. Chapter 8 proposes a risk-based framework for setting post-border management priorities based on the feasibility, benefits and costs of risk reduction. This chapter elucidates how knowledge generated from research in Chapters 2-7 can be used in a biosecurity risk management context. It shows that effective management post-border is possible even when pest organisms become relatively well established, and that the benefits gained from even limited successes have the potential to greatly outweigh the consequences of uncontrolled invasion. However, as unwanted species become increasingly widespread, management will become increasingly focussed on the protection of specific values. Chapter 9 extends some of the ideas proposed in Chapter 8, and considers a broad postborder management framework for marine pests. A comprehensive system should consist of vector management, surveillance, and incursion response that targets particular pests or suites of functionally similar species (e.g., biofouling organisms), coupled with generic vector management approaches that aim to reduce humanmediated transport of all organisms at a national scale. New Zealand's geographic isolation and low population, hence relatively low level of vector activity, makes the management of human-mediated pathways of spread entirely feasible in many circumstances. Hence, while there are clearly many challenges in the post-border management of marine pests, this is nonetheless a realistic goal, and probably moreso in New Zealand than in any other country in the world.</p>

Sponges in a Changing Climate: Survival of Agelas oroides in a Warming Mediterranean Sea

Sponges hold a key role in benthic environments, and specifically in the Mediterranean Sea. Past events of mass mortality in sponge communities have been linked to extended periods of high-temperature anomalies, yet it is unknown how a gradual change, such as the constant rise in global seawater temperatures, will affect biodiversity. Here we present a case study of Agelas oroides, a common massive sponge in the Mediterranean Sea, found at a wide depth range of 1–150 m. Last documented in the 1970s, A. oroides was considered lost from the Israeli coastal fauna. However, its recent rediscovery in mesophotic depths, where environmental conditions are stable, provided an opportunity to examine whether it can survive the present conditions in the shallow Israeli coast – where temperatures increased by 3°C during the past 60 years, while the nutrients concentration decreased following the damming of the Nile River. To test this hypothesis, A. oroides individuals were collected during winter from mesophotic sponge grounds (100–120 m) and transplanted to a shallow rocky habitat (10 m). Control individuals were transplanted back to the mesophotic habitat. Sponge survival, temperature, and nutrient concentrations were measured in both habitats. The shallow-transplanted sponges’ survival decreased only when the ambient temperature exceeded 28°C. In contrast, the control group at the mesophotic depth, where the temperature never rose above 20°C, survived the duration of the experiment. Our findings suggest that a prolonged period of high temperatures may constitute a major factor in A. oroides survival and disappearance from the Israeli shallow habitats.

Spatial genetic structure in the rock hyrax (Procavia capensis) across the Namaqualand and western Fynbos areas of South Africa — a mitochondrial and microsatellite perspective

The interplay between biotic and abiotic environments is increasingly recognized as a major determinant of spatial genetic patterns. Among spatial genetic studies, saxicolous or rock-dwelling species remain underrepresented in spite of their strict dependence on landscape structure. Here we investigated patterns and processes operating at different spatial (fine and regional scales) and time scales (using mitochondrial and microsatellite markers) in the rock hyrax (Procavia capensis (Pallas, 1766)). Our focus was on the western seaboard of South Africa and included two recognized biodiversity hotspots (Cape Floristic Region and Succulent Karoo). At fine spatial scale, significant genetic structure was present between four rocky outcrops in an isolated population, likely driven by the social system of this species. At a broader spatial scale, ecological dependence on rocky habitat and population-level processes, in conjunction with landscape structure, appeared to be the main drivers of genetic diversity and structure. Large areas devoid of suitable rocky habitat (e.g., the Knersvlakte, Sandveld, and Cape Flats, South Africa) represent barriers to gene flow in the species, although genetic clusters closely follow climatic, geological, and phytogeographic regions, possibly indicating ecological specialization or adaptation as contributing factors enforcing isolation. Taken together, our study highlights the need to consider both intrinsic and extrinsic factors when investigating spatial genetic structures within species.

First documented record of Chordeiles pusillus (Gould, 1861) (Caprimulgiformes, Caprimulgidae) in São Paulo state

This note presents the first documented record of Least Nighthawk, Chordeiles pusillus (Gould, 1861), in S&atilde;o Paulo state, Brazil. The species was observed on four occasions (January 31, April 25, and July 27, 2016; April 27, 2017) in a sandy-rocky habitat on the left bank of Grande river, Mira Estrela municipality. This record is at least 300 km from the previously known occurrences of the species.

Sympatric competitors have driven the evolution of temporal activity patterns in Cnemaspis geckos in Southeast Asia

It is often assumed that animals’ temporal activity patterns are highly conserved throughout evolution. While most geckos are nocturnal, the species in the Cnemaspis genus are mostly diurnal (only a few are nocturnal). This raises a question about the evolution of a diel niche in the Cnemaspis genus. Cnemaspis geckos are distributed across Southeast Asia and are often sympatric with Cyrtodactylus, another widespread gecko genus in the same area. Since both genera are mainly rocky habitat specialists, we hypothesize that Cyrtodactylus may influence the temporal activity pattern of Cnemaspis when they are sympatric through competition. By analyzing habitat data, diel activity, and the existence of sympatric Cyrtodactylus species across the phylogeny of the Cnemaspis genus, we found (1) strong phylogenetic signals in the habitat use trait but not in temporal activity, suggesting that the diel niche of this genus is more labile compared with habitat niche, and (2) a significant association with the temporal activity pattern of Cnemaspis and the sympatry between the two genera, with the former tending to be diurnal when they are sympatric. Originated from a diurnal common ancestor, the release from competition with Cyrtodactylus species might open an opportunity for some Cnemaspis species to shift to nocturnal niches.

Freshwater hydrozoan blooms alter activity and behaviour of territorial cichlids in Lake Tanganyika

Blooms of gelatinous zooplankton can represent dramatic environmental perturbations for aquatic ecosystems. Yet, we still know little about how blooms impact fitness-related behaviours of fish caught within their areas of effect, especially for freshwater systems. Here, we documented the behavioural impacts of freshwater hydrozoan ( Limnocnida tanganjicae ) blooms on a territorial cichlid ( Variabilichromis moorii ), as well as on the wider community of cichlids in a shallow-water rocky habitat of Lake Tanganyika. Compared with non-bloom conditions, V. moorii individuals in the midst of blooms reduced their swimming and territory defence activities (each by approx. 50%) but not their foraging or affiliative behaviours. Despite this reduction in activity, V. moorii could not entirely avoid being stung and preferred to remain closer to the rocky substrata as opposed to the more open demersal zone. Many other fishes similarly hid among the benthic substrata, changing the composition of the fish community in the demersal zone during bloom conditions. Reductions in activity could have multiple fitness-related implications for individual fish. Establishing the consequences of these behavioural changes is important for understanding the effects of gelatinous zooplankton blooms in freshwater systems.

Predicting important rockfish (Sebastes spp.) habitat from large-scale longline surveys for southern British Columbia, Canada

Rockfish, particularly yelloweye (Sebastes ruberrimus) and quillback (Sebastes maliger), are vulnerable to overfishing because they mature late and have affinity for shallow water (50–200 m) habitats. Because studies relating habitat characteristics with the distribution and presence of rockfishes at large scales (100s of kilometres) remain scarce, we sought to investigate the relationships between benthic characteristics with the presence–absence and abundance of rockfishes caught in longline surveys in nearshore waters of southern British Columbia. Habitat parameters were calculated from a 20 m resolution bathymetry layer. Yelloweye and quillback were examined separately and combined with 19 other rockfish species in a species aggregate (total rockfish); occurrence data were fitted with generalized linear mixed effects models, and abundance data were fitted with zero-inflated mixed effects models. The relationship between rockfish abundance with presence–absence and slope, distance to rocky habitat, and fine bathymetric position index suggests that these species prefer rocky, steep habitat. While underwater visual observation data offer measures of visual fish habitat and abundance, longline surveys may be a more cost-effective method for large-scale studies.

Morphological variability of Jania longifurca (Corallinales, Rhodophyta) in Galicia, northwestern Spain

Material of Jania J.V.Lamour. with a different morphology from the typical one attributed to J. longifurca Zanardini and J. rubens (L.) J.V.Lamour.—the only species in this habitat in Galicia—has been detected in the maerl beds of Galicia. This morphology consists on: thin intergenicula, an irregular pattern of dichotomies and secondary attachment discs that facilitate the refixation to the substrate, all of them similar to those of other southern species of Jania. Nevertheless, the integrative taxonomic study of this material and other collections from rocky habitat confirmed its identification as J. longifurca. Thereby, the atypical morphology with thin intergenicula and secondary attachment disc is dominant in samples of J. longifurca from maerl beds, while the samples from rocky environments showed the typical robust intergenicula. Moreover, molecular analysis resolved some phylogenetic affinities with samples from New Zealand, where this species is not recorded. It is concluded therefore the morphological variation related to the environment and it is evident the need of molecular studies to clarify this genus taxonomy, which is based fundamentally on morphological characters.

A new species of Corydalis (Fumariaceae) from Gansu (China)

A new species Corydalis qilianshanica Mikhailova (sect. Strictae (Fedde) Wendelbo) is described from Northwest China, Gansu Province, Nanshan mountain system, Qilian Shan (Richthofen Range). The species differs from C. stricta Stephan ex DC. by growth form with numerous persistent last year’s old stems, usually branched racemes, bipinnate leaves with flabellate segments, and larger basal leaves, as well as by rocky habitat.