Introduced Marine Pests Research Articles

A united front against marine invaders: Developing a cost‐effective marine biosecurity surveillance partnership between government and industry

Abstract Successful detection of introduced marine pests (IMP) relies upon effective surveillance. However, the expedience of responding following IMP detection is often dependent upon the relationship between regulators and stakeholders. Effective detection of IMP in areas such as commercial ports requires a collaborative approach, as port environments can be highly complex both above and below the water. This complexity can encompass physical, logistical, safety and legislative issues. With this in mind, the aquatic pest biosecurity section within the Department of Primary Industries and Regional Development (DPIRD) developed the State‐Wide Array Surveillance Program (SWASP) in collaboration with Western Australian Port Authorities and port industry stakeholders. The SWASP is primarily based on passive settlement arrays for IMP detection. Arrays are deployed at strategic locations within Ports. Marine growth samples collected from the arrays are processed using Next‐Generation Sequencing (NGS) to identify the presence of IMP within a specific geographical location. Over 8 years, participation in SWASP has grown from 3 to 11 ports, spanning over 11,000 km, from the tropical north to temperate south of Western Australia. The programme has proven to be highly effective as a means of fostering stakeholder involvement and, importantly for IMP surveillance. The growth and success of SWASP has continued primarily because of the commitment and farsightedness of the ports involved. The regular presence of the biosecurity regulator as a partner in SWASP has provided a consistent face for biosecurity and fostered good stakeholder relationships, ensuring there is a reliable and effective ongoing marine surveillance programme for the state. Synthesis and applications. Through a united and collaborative approach to marine biosecurity surveillance, port authorities, industry and biosecurity regulators have developed the State‐Wide Array Surveillance Program (SWASP) and closed a major gap in biosecurity surveillance. The SWASP collaboration uses passive settlement arrays and molecular analyses to provide regular marine pest surveillance from the tropics to temperate regions of Western Australia. The continued commitment has embedded valuable relationships between stakeholder and regulator ensuring ongoing surveillance in marine biosecurity for the state. The Western Australian SWASP example has inspired other jurisdictions around Australia to develop similar collaborative approaches which will have far‐reaching marine biosecurity benefits.

Environmental Emergency: Why Did the False Mussel Mytilopsis sallei Not Invade Darwin Harbour, Australia?

No introduced marine pests, also known as invasive marine species, were detected in a dry season survey in August 1998 in Darwin Harbour, Northern Territory, Australia. A postwet-season survey in March 1999 found extensive populations of the false mussel Mytilopsis sallei (Recluz, 1849) in the Cullen Bay Marina. An environmental emergency was declared and M. sallei were eliminated. The present paper examines possible reasons for the failure of M. sallei to establish outside Cullen Bay. Mytilopsis sallei is a fresh/brackish water species that naturally lives in low salinities. It is hypothesized that the osmotic shock of rapid movement from low salinity water in Cullen Bay to much higher salinities outside the marina killed the veligers when they were discharged through the entrance lock when it was opened to allow vessel movements. If it entered the harbour, M. sallei could possibly have established in low salinity water in the arms leading into the harbour and possibly have spread in northern Australia.

Sounding out pests: the potential of hydroacoustics as a surveillance and compliance tool in aquatic biosecurity

Shipping is the main method for goods transportation, accounting for approximately 60% of all global trade. Biofouling of these shipping vessels is a critical pathway for the introduction of non-indigenous species (NIS) across the world’s oceans. In order to reduce the likelihood of NIS introductions, appropriate biosecurity mechanism need to be in place, including maintaining high standards in vessel hygiene, such as zero secondary biofouling. Development of methodologies that can accurately quantify vessel biofouling without impeding maritime operations, while simultaneously providing effective biosecurity for the marine environment and resources, and mitigation of introduced marine pests would be highly advantageous. This study tests such a methodology. We conduct a proof-of-concept study that uses hydroacoustics to quantify the biofouling on a vessel’s hull, using surrogates for a vessel hull and biofouling. Based on a simple off-the-shelf single beam echosounder, the method was able to visually detect and quantify various biofouling mimics (ranging in height from 10 to 200 mm in height) at a slow tow speed (0.5 m/s). The efficacy of the hydroacoustic method was influenced by the movement of the echosounder, with the discriminating capability reduced to the detection of only larger mimics as the speed of movement increased. With further development, the use of hydroacoustics could become a viable biosecurity surveillance option for the mitigation of introduced marine pest incursions.

Macro-Fouling Faunal Assemblage in Hambantota Port

Invasive species recognized as one of the greatest threats to global biodiversity and biofouling on submerged structures within a port environments is one of the major pathways of invasions by Non Indigenous Species (NIS). Early detection and monitoring of such deleterious organisms is crucial, since control is nearly impossible once established. The present work is a baseline study for biofouling faunal assemblage in Hambantota Port. The study consisted of two stages; initial sampling for investigating existing biofouling assemblage and review sampling after 10 months in order to monitor the changes in community structure. Sampling followed an international protocol developed by Center for Research on Introduced Marine Pest (CRIMP). Samples were scraped from submerged hard substrata in 12 sampling sites with the assistance from divers. Organisms in scraped samples were identified to the nearest taxonomic level using taxonomic guides and databases. All together 90 species were recorded during the study. Among them, 72 species were recorded within the baseline sampling and additional 18 during review sampling. Highest number of species recorded from phylum Mollusca (54) followed by Arthropoda (11), Annelida (11), Chordata (5), Cnidaria (4),Echinodermata (3) and Bryozoa (2). Balanus amphitrite, Balanus tintinnabulum, were the most common species in baseline sampling while Chthamalus sp.1 and Cellana radiata in the review sampling. Balanus tintinnabulum, Clypidina notata, Cellana radiata, Thais echinata, Harmoniconus parvatus and Saccostrea cucullata were the common species found in both sampling. In baseline sampling, highest number of species was recorded from Oil Pier (31) while least number (1) was recorded in the outer harbour artificial island. In review sampling, highest species richness (12) recorded in west bank while least species richness (5) was recorded within the West Breakwater. The most noteworthy finding is that eight globally known invasive species which include, Rapana venosa, Phallusia nigra, Perna perna, Brachidontes pharaonis, Balanus amphitrite, Balanus reticulates, Balanus trigonus and Schizoporella errata were recorded. Among them Rapana venosa was recorded only in review sampling and rest in baseline sampling. Keywords: Biofouling, Non-indigenous species, Baseline study, Hambantota Port

Establishment of a taxonomic and molecular reference collection to support the identification of species regulated by the Western Australian Prevention List for Introduced Marine Pests

Introduced Marine Pests (IMP, = non-indigenous marine species) prevention, early detection and risk-based management strategies have become the priority for biosecurity operations worldwide, in recognition of the fact that, once established, the effective management of marine pests can rapidly become cost prohibitive or impractical. In Western Australia (WA), biosecurity management is guided by the Western Australian Prevention List for Introduced Marine Pests which is a policy tool that details species or genera as being of high risk to the region. This list forms the basis of management efforts to prevent introduction of these species, monitoring efforts to detect them at an early stage, and rapid response should they be detected. It is therefore essential that the species listed can be rapid and confidently identified and discriminated from native species by a range of government and industry stakeholders. Recognising that identification of these species requires very specialist expertise which may be in short supply and not readily accessible in a regulatory environment, and the fact that much publicly available data is not verifiable or suitable for regulatory enforcement, the WA government commissioned the current project to collate a reference collection of these marine pest specimens. In this work, we thus established collaboration with researchers worldwide in order to source representative specimens of the species listed. Our main objective was to build a reference collection of taxonomically vouchered specimens and subsequently to generate species-specific DNA barcodes suited to supporting their future identification. To date, we were able to obtain specimens of 75 species (representative of all but four of the pests listed) which have been identified by experts and placed with the WA Government Department of Fisheries and, where possible, in accessible museums and institutions in Australasia. The reference collection supports the fast and reliable taxonomic and molecular identification of marine pests in WA and constitutes a valuable resource for training of stakeholders with interest in IMP recognition in Australia. The reference collection is also useful in supporting the development of a variety of DNA-based detection strategies such as real-time PCR and metabarcoding of complex environmental samples (e.g. biofouling communities). The Prevention List is under regular review to ensure its continued relevance and that it remains evidence and risk-based. Similarly, its associated reference collection also remains to some extent a work in progress. In recognition of this fact, this report seeks to provide details of this continually evolving information repository publicly available to the biosecurity management community worldwide

Biosecurity monitoring of Harmful Algal Bloom (HAB) species in Western Australian waters: first confirmed record of Alexandrium catenella (Dinophyceae)

The Australian National System for the Prevention and Management of Introduced Marine Pest Incursions has identified seven Harmful Algal Bloom (HAB) toxic dinoflagellate species as target species of concern. Alexandrium minutum Halim, 1960, and Alexandrium cf. tamarense (Lebour) Balech, 1995, are currently known to occur in south-western estuaries and coastal waters but with no documented impact on the seafood industry or human health. Monitoring of these species is challenging, time-consuming, expensive, and often relies on traditional morphotaxonomy. This reports the first confirmed detection of another HAB species, Alexandrium catenella (Whedon and Kofoid) Balech, 1995, in Western Australia (WA), using both microscopic and molecular methods. The confirmed detection of A. catenella (A. pacificum Group IV genotype) in WA hopefully will motivate discussion about better monitoring and control of toxic HAB species.

First Record of Cheilostome Encrusting Bryozoan, Celleporaria volsella from Coastal Waters of Sri Lanka

Sri Lanka is an Island country with very high faunal diversity. Yet, many species remain to be uncovered due to lack of interest on biodiversity in the marine environment. Therefore, it is imperative to carry out comprehensive studies to unveil these mysterious organisms from our coastal waters. Biofouling community is one such group that needs due attention in terms of taxonomy and distribution. Bryozoans are diverse and widely spread group owing to their long history; dating back to early Ordovician Period. Yet, inconspicuous and poorly known to most part of the world. Although most are marine, these colonial invertebrates occur in fresh water habitats as well. They comprise the major component of fouling communities growing on substrates. Therefore, the present study was designed to investigate the diversity of encrusting bryozoans in Colombo Port. Biofouling assemblages were collected from eight sampling locations using settlement collectors based on those developed by the Center for Research on Introduced Marine Pests (CRIMP). The collectors were suspended in four different depths. The first set was 1 m below the water surface and others settled in 1 m increments. Monthly samples were collected from October 2014 to July 2015 from both replacing and permanently settled collectors. Specimens were identified microscopically observing fine morphological features. Findings of the present study demonstrate presence of taxonomically diverse bryozoan community in Colombo port. Among other bryozoans the remarkable finding was the record of colonies of Celleporaria volsella found in all the sampling locations. This is the first record of C. volsella from Sri Lankan coastal waters. C. volsella is very rare encrusting colonial bryozoans of the family Lepraliellidae, sub-order Flustrina, and order Cheilostomatida originally described from Solomon Island, Anusha Islands and Florida Islands. C. volsella can be distinguish from close relatives of the genus from size and shape of the primary orifice with pair of spiny processes, large suboral avicularia and elongate vicarious avicularia with a smooth, truncated spatulate distal rim. Keywords: Celleporaria volsella, Encrusting bryozoa, Colombo port, Sri Lanka

Public engagement for the detection of the introduced marine species Charybdis japonica in Western Australia

The introduced crab, Charybdis japonica, was captured in the Swan River Estuary in Western Australia during October 2012. This constitutes the second documented report of this species in Western Australia after a single specimen was reported in 2010 from a nearby estuary. Given the invasive history of this species in locations such as New Zealand, a rapid-response delimiting survey was conducted to assess the prevalence of this crab within this estuary. A large public engagement campaign was run concurrently with the delimiting survey to inform and enlist the recreational crab fishers that use the Swan River and other nearby estuaries to report any more specimens that they caught. These activities yielded a total of three specimens, all handed in by recreational fishers as a result of the public engagement campaign. All three specimens were caught within a very limited area within the estuary, approximately 8 kilometres from the entrance. The two specimens that were able to be sexed were mature males, with carapace widths of 10.1 and 10.3 mm. The very small number of specimens caught, relative to the abundant native species indicates that C. japonica may be relatively scarce in the Swan River Estuary. This result highlights the importance of engaging members of the public to help detect introduced marine pest species in the early stages of incursions.

Catch me if you can! The story of a colonial ascidian’s takeover bid in Western Australia

In 2010, Didemnum perlucidum F. Monniot, 1983, a potentially invasive colonial ascidian, was found for the first time in Western Australia (WA). During routine introduced marine pest monitoring along the WA coast in 2011–2012, the Department of Fisheries confirmed additional disjunct populations in a span of ~ 2,800 km along the coast. Colonies of the ascidian were apparently flourishing in water temperatures from tropical through to temperate. Colour was not a reliable detection method for this colonial ascidian. Colonies in winter showed the expected senescence, becoming smaller, friable and often partially detached from the substrate. While winter monitoring would reduce likelihood of detection, it may present the best opportunity for eradication. Due to the widespread distribution, eradication of D. perlucidum is now unlikely. However, implementing local control measures to protect high value areas, such as marine parks or protected areas, from incursions remains feasible. A robust monitoring program is vital to detecting D. perlucidum early in its invasion history, and that would provide the best opportunity for local eradication effort.

Monitoring for introduced marine pests for the Gorgon LNG Project

Chevron Australia Pty Ltd is constructing a major gas processing plant at Barrow Island, WA. There are also substantial marine environmental values along with the widely known terrestrial environmental values of Barrow Island. Chevron has adopted an extensive, proactive program to protect the Barrow Island marine environment from introduced marine pest species (IMP), including mechanisms to prevent their arrival, a monitoring program to detect any IMP that do arrive, and action plans to be used should a pest species be detected. A monitoring strategy based on the national IMP monitoring protocols has been developed for Barrow Island. Remote operated vehicle (ROV) transects are made at six monthly intervals, at a combination of sites within and outside operational areas. The ROV surveys are supplemented by beam trawl sampling of biota in sandy areas. Quarterly monitoring occurs at four sites along the east coast of Barrow Island, using shoreline visual searches, settlement plates and sediment cores for toxic dinoflagellates. A similar quarterly sampling program has been established at the major supply bases at Henderson, south of Perth, and Dampier. This is to provide early warning should an IMP be detected in either locality. The combination of prevention, monitoring and response is a cutting edge response designed to prevent the introduction of IMP to Barrow Island waters.

How useful are port surveys focused on target pest identification for exotic species management?

Monitoring surveys are an important tool for detecting new arrivals of exotic species, for documenting patterns of invasion, and exotic species impacts. Faced with time and cost constraints, these surveys are increasingly focused on lists of target pest species, identified as being most likely to arrive and cause significant harm. We used the national survey of Australian international ports for introduced marine pests as a case study to assess: (1) the taxonomic rigor of surveys focused on detection of target species; and (2) how the ability of port surveys to inform invasion patterns is dependent on taxonomic approach. Our analysis of the 46 available reports revealed common sub-optimal taxonomic practices that compromised their utility to identify abiotic conditions that are good predictors of biological invasion. Thus, although surveys for target species may provide information on the distribution of a handful of species, they may fail to do much else.

Trace Metal Concentrations in the Little Penguin (Eudyptula minor) from Southern Victoria, Australia

Little Penguins (Eudyptula minor) are among the smallest of the warm-climate penguins (Stonehouse, 1975). Part of the family Spheniscidae, Little Penguins breed at several points along the southern coast of Australia and around Tasmania, mainly on offshore islands or parts of the coast where access by mammalian predators is reduced. In Victoria, the two most famous and accessible penguin colonies are on Philip Island in Westernport Bay, and Middle Island in southwest Victoria (Fig. 1). Middle Island lies just off-shore from the coastal city of Warrnambool, approximately 260 km from Melbourne, and fringes the Merri Marine Sanctuary. Although southwest Victoria is often considered to be a relatively uncontaminated region, because of its low scale industrial base and the distance from major sources of metal pollution, the island’s local marine environment may be influenced by the nearby municipal waste water treatment plant outfall and contaminants in the Merri River, whose estuary fringes the northern shore of the island. Philip Island is approximately 140 km from Melbourne, on the southern, ocean side of Westernport Bay. Westernport Bay is one of Victoria’s most important embayments and has many environmental values, from its important seagrass beds to the extensive mangrove and saltmarsh fringes. Some of the threats to the bay include urban and agricultural runoff, sedimentation, and turbidity from catchment, shipping and port activities (dredging of shipping channels and berths, and associated threat of oil spills and pollution), introduced marine pests, and removal of saltmarshes and mangroves for other land uses (Central Coastal Board, 2003). There have been few studies of contaminants in Australian birds, and only one previous study of metals in Australian Little Penguins (Gibbs, 1995). Little Penguins are an ideal indicator of contaminant accumulation in the inshore coastal environment, because they are higher level predators, feeding primarily on fish and squid within defined feeding areas close to their breeding grounds, and contaminant concentrations can be compared with penguins of the higher, less polluted latitudes of the Southern Ocean and Antarctic. In this baseline survey, we investigated the concentrations of a range of metals, including As, Cd, Cr, Cu, Fe, Hg, Mn, Mo, Pb, and Zn, in the pectoral muscles and livers of male and female Little Penguins on Phillip Island and Middle Island. Herein we report our results, and examine any localized differences in metal contamination in the penguins.

Desiccation tolerance of the introduced marine green alga Codium fragile ssp. tomentosoides – clues for likely transport vectors?

The invasive marine green macroalga Codium fragile ssp. tomentosoides is now considered to be an introduced marine pest along the northwest Atlantic and southern Australian coasts. International or domestic translocation of C. fragile ssp. tomentosoides is usually attributed to the fouling of ship hulls or shellfish, particularly oysters. A likely domestic vector is shipboard transport, involving the translocation of whole thalli or fragments entangled in fishing nets, ropes, etc. that are then released in a previously unaffected area. Here we investigated the survival of C. fragile ssp. tomentosoides under emersed conditions, simulating shipboard transport. C. fragile ssp. tomentosoides was able to survive periods of emersion of up to 90 days in high relative air humidity. Net photosynthesis remained positive at about 50% of the rates of submersed control thalli. After 2 days of emersion and 4 days of rehydration under submersed conditions thalli recover to their initial net photosynthesis rates. Hence, C. fragile ssp. tomentosoides is likely to survive long shipboard journeys entrapped in fishing nets, anchor wells or other protected, high-humidity areas of a vessel. Furthermore, C. fragile ssp. tomentosoides may survive emersion on an exposed deck during short trips, especially in cooler conditions such as at night. The incursion sites of C. fragile ssp. tomentosoides in Australia are generally in modified environments, often associated with shipping-related infrastructure such as wharves, jetties, rip rap, and moorings.

Introduced and cryptogenic species in Port Phillip Bay, Victoria, Australia

Port Phillip Bay (PPB) is a large (1,930 km2), temperate embayment in southern Victoria, Australia. Extensive bay-wide surveys of PPB have occurred since 1840. In 1995/1996 the Commonwealth Scientific and Industrial Research Organization (CSIRO) Centre for Research on Introduced Marine Pests (CRIMP) undertook an intensive evaluation of the region with the aims of developing a comprehensive species list of native and introduced biota and contrasting previous bay-wide assessments with a current field survey in order to detect new incursions and discern alterations to native communities. Two methods were used to meet these aims: a re-evaluation of regional museum collections and published research in PPB to identify and determine the timing of introductions; and field surveys for benthic (infauna, epifauna and encrusting) organisms between September 1995 to March 1996. One hundred and sixty introduced (99) and cryptogenic (61) species were identified representing over 13% of the recorded species of PPB. As expected, the majority of these are concentrated around the shipping ports of Geelong and Melbourne. Invasions within PPB appear to be increasing, possibly due to an increase in modern shipping traffic and an increase in aquaculture (historically associated with incidental introductions); however the records of extensive biological surveys suggest that this may, in part, be an artefact of sampling effort. In contrast to Northern Hemisphere studies, PPB (and Southern Hemisphere introductions in general) have significantly different suites of successfully invading taxa. PPB is presented as one of the most invaded marine ecosystems in the Southern Hemisphere.

Developing the options for managing marine pests: specificity trials on the parasitic castrator, Sacculina carcini, against the European crab, Carcinus maenas, and related species.

The impacts of introduced marine pests are becoming increasingly apparent, prompting interest in the possibility of their biological control. We undertook laboratory and field experiments on host selection of one potential control agent (the endoparasitic barnacle, Sacculina carcini) against its natural host (the widely invasive European shore crab, Carcinus maenas) and several confamilial and more distantly related crustaceans. For comparison, we also tested host specificity in a related parasitic barnacle, Heterosaccus lunatus. The results confirm indistinct behavioral host selection in S. carcini, indicate very different mechanisms for host selection by S. carcini and H. lunatus (which could be related to differences between the two species in attachment points), and suggest host specificity in S. carcini depends on interactions between the parasite and the host's physiology. Development of convincing safety trials for marine parasites like S. carcini, in which the infective stage is a planktonic larva, will be more difficult than for many terrestrial parasites and will require detailed knowledge of the parasite's behavior and physiological interaction with its hosts.

The apparent eradication of a locally established introduced marine pest

Once a marine invader has become established, its subsequent control has rarely been attempted. We report the first apparently successful eradication of a locally well-established introduced marine pest. A previously unknown species of sabellid polychaete (now described as Terebrasabella heterouncinata arrived as an epizoic contaminant on South African abalone imported to California for commercial aquaculture research. In 1996, we detected an established sabellid population at an intertidal site near Cayucos, California (35 °45'N, 120 °95'W). To mitigate the impact of this introduced marine pest at this site, and prevent or slow its geographic spread, we proposed an eradication program based on the epidemiological theory of the threshold of transmission. Specifically, we removed 1.6 million of the most highly susceptible and preferred host in the intertidal area; the black turban snail, Tegula funebralis. A screen was also installed at the associated abalone mariculture facility to eliminate release of additional infested material (the source of the established sabellid population) and all such material was removed from the intertidal area. Using transect surveys and mark and recapture studies, we monitored the success of the eradication effort. Transmission of the pest can no longer be detected. Hence, the established sabellid population has apparently been eradicated. This discovery demonstrates that some alien marine pests can be eradicated and supports development of new proactive approaches to the management of other exotic marine pests.