Bilge water as a vector for the spread of marine pests: a morphological,metabarcoding and experimental assessment

Vessel movements are considered the primary anthropogenic pathway for the secondary spread of marine non-indigenous species. In comparison to the well-studied mechanisms of hull fouling and ballast water, the importance of bilge water for domestic and cross-regional spread of non-indigenous species is largely unknown and has the potential to compromise the overall effectiveness of biosecurity management actions. In this study, the diversity and abundance of biological material contained in bilge water from 30 small vessels (<20 m) was assessed using traditional and molecular identification tools (metabarcoding of the 18S rRNA gene). Laboratory-based studies were also used to investigate the relationship between voyage duration and propagule success. A large taxonomic diversity in organisms was detected, with 118 and 45 distinct taxa identified through molecular and morphological analyses, respectively. Molecular techniques identified five species recognised as non-indigenous to the study region in 23 of the 30 bilge water samples analysed. Larvae and fragments passed through an experimental bilge pump system relatively unharmed. Time spent in the bilge sump was found to affect discharge success, particularly of short-lived and sensitive larvae, but survival for 3 days was observed. Our findings show that bilge water discharges are likely to pose a non-negligible biosecurity threat and that further research to identify high-risk vessel operating profiles and potential mitigation measures are warranted.     

Assessment of possible ecological risks and hazards of transgenic fish with implications for other sexually reproducing organisms

Transgenic technology is developing rapidly; however, consumers and environmentalists remain wary of its safety for use in agriculture. Research is needed to ensure the safe use of transgenic technology and thus increase consumer confidence. This goal is best accomplished by using a thorough, unbiased examination of risks associated with agricultural biotechnology. In this paper, we review discussion on risk and extend our approach to predict risk. We also distinguish between the risk and hazard of transgenic organisms in natural environments. We define transgene risk as the probability a transgene will spread into natural conspecific populations and define hazard as the probability of species extinction, displacement, or ecosystem disruption given that the transgene has spread. Our methods primarily address risk relative to two types of hazards: extinction which has a high hazard, and invasion which has an unknown level of hazard, similar to that of an introduced exotic species. Our method of risk assessment is unique in that we concentrate on the six major fitness components of an organism's life cycle to determine if transgenic individuals differ in survival or reproductive capacity from wild type. Our approach then combines estimates of the net fitness parameters into a mathematical model to determine the fate of the transgene and the affected wild population. We also review aspects of fish ecology and behavior that contribute to risk and examine combinations of net fitness parameters which can lead to invasion and extinction hazards. We describe three new ways that a transgene could result in an extinction hazard: (1) when the transgene increases male mating success but reduces daily adult viability, (2) when the transgene increases adult viability but reduces male fertility, and (3) when the transgene increases both male mating success and adult viability but reduces male fertility. The last scenario is predicted to cause rapid extinction, thus it poses an extreme risk. Although we limit our discussion to aquacultural applications, our methods can easily be adapted to other sexually reproducing organisms with suitable adjustments of terminology.     

AUTECOLOGY AND THE FILLING OF ECOSPACE: KEY METAZOAN RADIATIONS

Abstract:  All possible combinations of six tiering positions in relation to the substratum/water interface, six motility levels and six feeding strategies define a complete theoretical ecospace of 216 potential modes of life for marine animals. The number of modes of life actually utilized specifies realized ecospace. Owing to constraints of effectiveness and efficiency the modern marine fauna utilizes only about half the potential number of modes of life, two-thirds of which (62 of 92) are utilized by animals with readily preserved, mineralized hard parts. Realized ecospace has increased markedly since the early evolution of animal ecosystems. The Ediacaran fauna utilized at most 12 modes of life, with just two practised by skeletal organisms. A total of 30 modes of life are recorded in the Early and Middle Cambrian, 19 of which were utilized by skeletal organisms. The other 11 are documented from soft-bodied animals preserved in the Chengjiang and Burgess Shale Konservat-Lagerstätten. The number of modes of life utilized by skeletal organisms increased by more than 50 per cent during the Ordovician radiation to a Late Ordovician total of 30. Between the Late Ordovician and the Recent the number of utilized modes of life has doubled again. The autecological and taxonomic diversity histories of the marine metazoa appear to be broadly parallel, and future studies of theoretical ecospace utilization should provide more detailed tests of pattern and process in the ecological history of the metazoa.     

Epidemiological investigation into the re-emergence and control of an outbreak of infectious salmon anaemia in the Shetland Islands, Scotland

Infectious salmon anaemia (ISA) is an orthomyxoviral disease, primarily affecting marine-phase farmed Atlantic salmon, which can result in high levels of mortality. ISA first emerged in Norway in the 1980s and subsequently has occurred in Canada, the USA, the Faeroe Islands and Chile. An outbreak occurred in Scotland in 1998-1999, but was eradicated at a cost of over pounds sterling 20M. The epidemiology of a new outbreak of ISA in the Scottish Shetland Islands during 2008-2009 is described. Six sites have been confirmed ISA-positive. Spread of the virus via transport of fish between marine sites, harvest vessels, smolts and wild fish appears to have been of little or no importance, with spread primarily associated with marine water currents. The use of management areas by Marine Scotland to control the event appears to have been effective in restricting spread to a small area. This localised outbreak contrasts with the 1998-1999 outbreak that spread over a wide geographic area with transported fish and harvest vessels. The development and application of industry codes of good practice, good husbandry and biosecurity practices, limited marine site-to-site movement of live fish and improved disinfection of vessels and processing plant waste that occurred subsequent to the 1998-1999 outbreak may explain the localised spread of infection in 2008-2009. Depopulation of confirmed sites has been achieved within 7 wk (mean = 3.7 wk); however, it is likely that subclinical infection persisted undetected for months on at least 1 site. The origin of the 2008-2009 outbreak remains unknown. Potential sources include evolution from a local reservoir of infection or importation. Synchronous fallowing of management areas, with good husbandry and biosecurity, reduces the risk of ISA recurring. Movement of fish between sites in different management areas represents the greatest risk of regional-scale spread, should this occur.     

Distribution of thermophilic endospores in a temperate estuary indicate that dispersal history structures sediment microbial communities

Endospores of thermophilic bacteria are found in cold and temperate sediments where they persist in a dormant state. As inactive endospores that cannot grow at the low ambient temperatures, they are akin to tracer particles in cold sediments, unaffected by factors normally governing microbial biogeography (e.g., selection, drift, mutation). This makes thermophilic endospores ideal model organisms for studying microbial biogeography since their spatial distribution can be directly related to their dispersal history. To assess dispersal histories of estuarine bacteria, thermophilic endospores were enriched from sediments along a freshwater‐to‐marine transect of the River Tyne in high temperature incubations (50°C). Dispersal histories for 75 different taxa indicated that the majority of estuarine endospores were of terrestrial origin; most closely related to bacteria from warm habitats associated with industrial activity. A subset of the taxa detected were marine derived, with close relatives from hot deep marine biosphere habitats. These patterns are consistent with the sources of sediment in the River Tyne being predominantly terrestrial in origin. The results point to microbial communities in estuarine and marine sediments being structured by bi‐directional currents, terrestrial run‐off and industrial effluent as vectors of passive dispersal and immigration.     

Integrated environmental risk assessment approach for transportation modes

Abstract

The main aim of this study is to develop and implement new integrated environmental risk assessment for transportation activities. With this purpose, environmental risks occur from transportation activities from different transportation modes which are air, road, sea and rail are determined. Transportation modes are compared with the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) approach in order to obtain importance weights and impact categories of air, soil and water are used as criteria where the weights are determined with Analytical Hierarchy Process (AHP). For the risk assessment process, Failure Mode and Effect Analysis (FMEA) has been used and prioritizations of risks are calculated with weights of the calculated transportation modes. In the study, integrated multi-criteria decision-making methods with the classic FMEA method with different categories of impacts reveal new multidimensional perspective to classic environmental risk assessment methods.     

Risk factors for fouling biomass: evidence from small vessels in Australia

Abstract

Invasive non-indigenous species (NIS) are a threat to marine biodiversity and marine reliant industries. Recreational vessels are recognised as an important vector of NIS translocation, particularly domestically. This paper reports on a novel application of multilevel modelling and multiple imputation in order to quantify the relationship between biofouling biomass (wet weight) and the vessel-level characteristics of recreational and fishing vessels. It was found that the number of days since the vessel was last cleaned strongly related to the biofouling biomass, yet differed dependent on vessel type. Similarly, the median number of trips undertaken was related to the biofouling biomass, and varied according to the type of antifouling paint (AF) used. No relationship was found between vessel size and biofouling biomass per sample unit. To reduce the spread of NIS, vessel owners should use an AF paint suitable to their vessel’s operational profile, and follow a maintenance schedule according to the paint manufacturer’s specifications.     

Disease-translocation across geographic boundaries must be recognized as a risk even in the absence of disease identification: the case with Australian Sardinops

In 1995 and 1998/99 single species massmortalities of sardine/pilchard Sardinopssagax (Clupeidae) spread rapidly throughoutthis species' range in Australia from thecentral coast of South Australia, dramaticallydecreasing the population size and representingthe two most extensive mass mortalitiesrecorded for marine organisms. The behavior ofeach epizootic indicated that an exoticpathogen was responsible, with the fatal agentshown to be a previously unknown herpesvirus. The focal origin of both events from a limitedregion within the extensive Australian range ofS. sagax was not random. Tuna(Thunnus maccoyii) feedlots located in the sameregion as the epizootics' origins areresponsible for delivering to the marineenvironment the largest quantities ofS. sagax imported into Australia, which providesqualitative evidence of a link between the twoevents and imported S. sagax. This linkprovides an example of the need to undertake areview of the current international standardsfor import risk analysis (IRA) that requires adisease to be identified before it can beconsidered a risk. Regardless of the identityof the disease agents responsible, casehistories of mass mortalities need to be givendue consideration in both deciding whether toinstigate an IRA and also form part of the IRA. Identification of a hazard should thus not berestricted to dealing only with identifiablediseases, but should also embrace casehistories of epizootic events linked to (a)previously unidentified pathogens and (b)translocation of particular species betweengeographically separate populations.     

Marine invasion history and vector analysis of California: a hotspot for western North America

Aim We examine the regional dominance of California as a beachhead for marine biological invasions in western North America and assess the relative contribution of different transfer mechanisms to invasions over time. Location Western North America (California to Alaska, excluding Mexico). Methods We undertook extensive analysis of literature and collections records to characterize the invasion history of non‐native species (invertebrates, microalgae and microorganisms) with established populations in coastal marine (tidal) waters of western North America through 2006. Using these data, we estimated (1) the proportion of first regional records of non‐native species that occurred in California and (2) the relative contribution of transfer mechanisms to California invasions (or vector strength) over time. Results Excluding vascular plants and vertebrates, we identified 290 non‐native marine species with established populations in western North America, and 79% had first regional records from California. Many (40–64%) of the non‐native species in adjacent states and provinces were first reported in California, suggesting northward spread. California also drives the increasing regional rate of detected invasions. Of 257 non‐native species established in California, 59% had first regional records in San Francisco Bay; 57% are known from multiple estuaries, suggesting secondary spread; and a majority were attributed to vessels (ballast water or hull fouling) or oysters, in some combination, but their relative contributions are not clear. For California, more than one vector was possible for 56% of species, and the potential contribution of ballast water, hull fouling and live trade increased over time, unlike other vectors. Main conclusions California, especially San Francisco Bay, plays a pivotal role for marine invasion dynamics for western North America, providing an entry point from which many species spread. This pattern is associated historically with high propagule supply and salinity. Any effective strategies to minimize new invasions throughout this region must (1) focus attention on California and (2) address current uncertainty and future shifts in vector strength.     

The movement ecology of seagrasses

A movement ecology framework is applied to enhance our understanding of the causes, mechanisms and consequences of movement in seagrasses: marine, clonal, flowering plants. Four life-history stages of seagrasses can move: pollen, sexual propagules, vegetative fragments and the spread of individuals through clonal growth. Movement occurs on the water surface, in the water column, on or in the sediment, via animal vectors and through spreading clones. A capacity for long-distance dispersal and demographic connectivity over multiple timeframes is the novel feature of the movement ecology of seagrasses with significant evolutionary and ecological consequences. The space–time movement footprint of different life-history stages varies. For example, the distance moved by reproductive propagules and vegetative expansion via clonal growth is similar, but the timescales range exponentially, from hours to months or centuries to millennia, respectively. Consequently, environmental factors and key traits that interact to influence movement also operate on vastly different spatial and temporal scales. Six key future research areas have been identified.     

Selectivity in vector management: an investigation of the effectiveness of measures used to prevent transport of non-indigenous species

Measures taken to control the spread of non-indigenous species by human vectors may act selectively by providing effective protection against some (but not all) species. Toxic antifouling paints are used by boat owners to prevent the development of fouling assemblages on the hulls of their boats, which reduce vessel speed and maneuverability. By reducing fouling, these paints also prevent transport of non-indigenous species. Using experimental surfaces mimicking boat hulls, we evaluated the effectiveness and selectivity of (1) antifouling paints, and (2) manual, in-water hull cleaning for preventing the transport of marine sessile invertebrates by recreational vessels. Different types of antifouling paints provided effective protection only against barnacles and bivalves. Other fouling taxa occurred on experimental surfaces after a period of only 2 months. Manual hull cleaning did not remove fouling completely, and even enhanced the risk of subsequent recruitment by some fouling organisms. Up to six times more individuals and colonies recruited to boat surfaces from which the existing fouling organisms had been removed manually than to surfaces that had been sterilized or contained intact fouling assemblages. Bivalves, colonial and solitary ascidians, encrusting bryozoans, hydroids, tubiculous polychaetes, and sponges consistently recruited in greatest abundance to manually cleaned surfaces. Individual taxa responded in complex, but predictable ways to the biogenic cues left by manual cleaning, so that different suites of organisms colonized surfaces that had originally contained fouling assemblages of local or non-local origin. Our study shows that widely adopted measures to control the spread of non-indigenous species by human vectors are often highly selective and, while effective for some taxa, do not prevent the transport of others.     

Enumeration and speciation of enterococci found in marine and intertidal sediments and coastal water in southern California

AIMS: To determine the levels and species distribution of enterococci in intertidal and marine sediments and coastal waters at two beaches frequently in violation of bacterial water standards. METHODS AND RESULTS: Faecal indicator bacteria were extracted from sediment and enumerated using membrane filtration. High levels of enterococci were detected in intertidal sediments in a seasonal river and near a storm drain outlet. Low levels were found in marine sediments at 10 m depths and in surf zone sand. Bacterial isolates presumptively identified as Enterococcus on mEI media were speciated. The predominant species found in both water and sediment included Enterococcus faecalis, Enterococcus faecium, Enterococcus hirae, Enterococcus casseliflavus and Enterococcus mundtii. A number of isolates (11-26%) from regulatory water samples presumptively identified as enterococci on mEI media were subsequently identified as species other than Enterococcus. At both study sites, the distribution of species present in water was comparable with those in sediments and the distribution of species was similar in water samples passing and exceeding bacterial indicator standards. CONCLUSIONS: High levels of Enterococcus in intertidal sediments indicate retention and possible regrowth in this environment. SIGNIFICANCE AND IMPACT OF THE STUDY: Resuspension of enterococci that are persistent in sediments may cause beach water quality failures and calls into question the specificity of this indicator for determining recent faecal contamination.     

Antifouling enzymes and the biochemistry of marine settlement

Antifouling coatings are used extensively on marine vessels and constructions, but unfortunately they are found to pose a threat to the marine environment, notably due to content of metal-based biocides. Enzymes have repeatedly been proposed as an alternative to traditional antifouling compounds. In this review, the enzymes claimed to hold antifouling activity are classified according to catalytic functions. The enzyme functions are juxtaposed with the current knowledge about the chemistry of settlement and adhesion of fouling organisms. Specific focus will be on bacteria, microalgae, invertebrate larvae and macroalgae zoospores. Two main concepts in enzyme-based antifouling are identified: breakdown of adhesive components and catalytic production of repellent compounds in-situ. The validity of the various modes of action is evaluated and the groups of enzymes with the highest potential are highlighted.     

胶州湾海水、海洋生物体中重金属含量的研究

研究了胶州湾海水、海洋生物体中重金属含量.结果表明,沿岸河口地区海水中重金属污染主要受沿岸工业排放废水的影响;海洋生物体内重金属含量不仅受海水中的重金属含量大小的支配,温度对其也有一定的影响.海洋生物体中重金属含量为底栖生物大于鱼类,以沉积物为主要饵料的杂食性底栖动物内重金属含量大于鱼类;海洋生物对于Cu比其它重金属具有较强的富集能力.     

Selection of critical habitats for bottlenose dolphins (Tursiops truncatus) based on behavioral data,in relation to marine traffic in the Istanbul Strait,Turkey

Marine traffic is a significant source of disturbance to the bottlenose dolphin population in the Istanbul Strait, Turkey. To determine the importance of this threat, behavioral data together with sighting data of both dolphins and marine vessels were assessed for 2012. The current study suggests that the Istanbul Strait is used mostly as a foraging ground for bottlenose dolphins. Nonetheless, in the same area there is intense marine traffic as well as increase of industrial fishing activities in autumn. The findings of this study indicated that high‐speed ferries and high‐speed boats were the most significant source of disturbance. Moreover, increased densities of fishing vessels resulted in a drastic decline of dolphin sightings. This study highlights that vessel type, speed, distance, and density have a cumulative negative effect on dolphins. In order to mitigate the impacts of vessels, it is necessary to establish managed areas in the Istanbul Strait. Such proposed areas should limit speed and density of marine traffic and have specific restrictions on vessel routes. We propose three different seasonal managed areas according to their values as critical habitat for bottlenose dolphins in the strait.     

胶州湾海水,海洋生物体中重金属含量的研究

研究了胶州湾海水、海洋生物体中重金属含量 .结果表明 ,沿岸河口地区海水中重金属污染主要受沿岸工业排放废水的影响 ;海洋生物体内重金属含量不仅受海水中的重金属含量大小的支配 ,温度对其也有一定的影响 .海洋生物体中重金属含量为底栖生物大于鱼类 ,以沉积物为主要饵料的杂食性底栖动物内重金属含量大于鱼类 ;海洋生物对于Cu比其它重金属具有较强的富集能力 .     

Bacterial and archaeal communities inhabiting mussels,sediment and water in Indonesian anchialine lakes

Anchialine lakes are a globally rare and unique ecosystem consisting of saline lakes surrounded by land and isolated from the surrounding marine environment. These lakes host a unique flora and fauna including numerous endemic species. Relatively few studies have, however, studied the prokaryote communities present in these lakes and compared them with the surrounding ‘open water’ marine environment. In the present study, we used a 16S rRNA gene barcoded pyrosequencing approach to examine prokaryote (Bacteria and Archaea) composition in three distinct biotopes (sediment, water and the mussel Brachidontes sp.) inhabiting four habitats, namely, three marine lakes and the surrounding marine environment of Berau, Indonesia. Biotope and habitat proved significant predictors of variation in bacterial and archaeal composition and higher taxon abundance. Most bacterial sequences belonged to OTUs assigned to the Proteobacteria. Compared to sediment and water, mussels had relatively high abundances of the classes Mollicutes and Epsilonproteobacteria. Most archaeal sequences, in turn, belonged to OTUs assigned to the Crenarchaeota with the relative abundance of crenarchaeotes highest in mussel samples. For both Bacteria and Archaea, the main variation in composition was between water samples on the one hand and sediment and mussel samples on the other. Sediment and mussels also shared much more OTUs than either shared with water. Abundant bacterial OTUs in mussels were related to organisms previously obtained from corals, oysters and the deepsea mussel Bathymodiolus manusensis. Abundant archaeal OTUs in mussels, in contrast, were closely related to organisms previously obtained from sediment.     

Fouling in your own nest: vessel noise increases biofouling

Globally billions of dollars are spent each year on attempting to reduce marine biofouling on commercial vessels, largely because it results in higher fuel costs due to increased hydrodynamic drag. Biofouling has been long assumed to be primarily due to the availability of vacant space on the surface of the hull. Here, it is shown that the addition of the noise emitted through a vessel’s hull in port increases the settlement and growth of biofouling organisms within four weeks of clean surfaces being placed in the sea. More than twice as many bryozoans, oysters, calcareous tube worms and barnacles settled and established on surfaces with vessel noise compared to those without. Likewise, individuals from three species grew significantly larger in size in the presence of vessel noise. The results demonstrate that vessel noise in port is promoting biofouling on hulls and that underwater sound plays a much wider ecological role in the marine environment than was previously considered possible.     

Complementary Transformations of Buried Organic Residues and the Ambient Sediment: Results of Long-Term Taphonomic Experiments

Long-term (18 month) experiments were conducted, burying soft bodied organisms (Artemia salina, Crustacea) in marine sediment. For the first time in experimental taphonomy, the mineralogical transformation of the sediment that accompanied the process of decomposition was correlated with the degree of preservation. To obtain different quantitative characteristics of preservation, we used four dilutions of marine water (marine water: to fresh water as 1: 0; 1: 1, 1: 4, 1: 9).It was shown that higher dilutions corresponded to lower degrees of preservation. The proportion of kaolinite decreased in the marine sediment and, accordingly, the amorphous phase increased; in the diluted variants, the opposite pattern was revealed: the crystalline kaolinite phase increased and the amorphous phase decreased. Since no differences in the chemical composition of the residues from different dilutions were identified, the effect of sea salt concentration on preservation was considered to be negligible. A plausible hypothesis suggested that dissolving of kaolinite slows of organic decomposition and the beginnings of mineralization. Due to the acidic hydrolysis of kaolinite, Al cations appear in the solution; subsequently proteins are converted into insoluble forms, and thus escape from bacterial degradation. These taphonomic experiments reveal some overlooked physicochemical aspects important for the mechanisms of exceptional preservation.     

Starting the invasion pathway: the interaction between source populations and human transport vectors

Human transport hubs, such as shipping ports, airports and mail centers are important foci for the spread of non-indigenous species. High relative abundance in a transport hub has been proposed as a correlate of invasion success, since abundant species are thought more likely to colonize vectors and to be transported more frequently. We here evaluate the relative importance of vector characteristics and local source assemblages in determining the pool of species that is transported by hull fouling on recreational boats. We compared the resident fouling communities of three recreational boat harbors in Australia with the assemblages on the hulls of boats that travel between them. We used data on the recent travel and maintenance history of the boats to evaluate correlates of transport probability and the potential for intra-coastal spread of fouling organisms. Invertebrate assemblages on heavily fouled vessels reflected the composition of biotic assemblages within the marina in which they were moored, but by itself, relative abundance in the source port was not a reliable predictor of transport probability. More important was the age of the antifouling paint on the vessels’ hulls, which acted selectively on some groups of organisms. Movements of vessels were characterized by “fidelity” (vessels remaining close to homeport) interspersed with “promiscuity” (vessels traveling to a diverse pool of destinations). In an infested harbor, measures taken to increase the resistance of vectors to colonization by the invader should be effective in slowing the rate of spread to other locations, by decreasing the overall frequency of transport.