Invasive Mussel Research Articles

Attachment of zebra and quagga mussel adhesive plaques to diverse substrates

Like marine mussels, freshwater zebra and quagga mussels adhere via the byssus, a proteinaceous attachment apparatus. Attachment to various surfaces allows these invasive mussels to rapidly spread, however the adhesion mechanism is not fully understood. While marine mussel adhesion mechanics has been studied at the individual byssal-strand level, freshwater mussel adhesion has only been characterized through whole-mussel detachment, without direct interspecies comparisons on different substrates. Here, adhesive strength of individual quagga and zebra mussel byssal plaques were measured on smooth substrates with varying hydrophobicity—glass, PVC, and PDMS. With increased hydrophobicity of substrates, adhesive failures occurred more frequently, and mussel adhesion strength decreased. A new failure mode termed 'footprint failure' was identified, where failure appeared to be adhesive macroscopically, but a microscopic residue remained on the surface. Zebra mussels adhered stronger and more frequently on PDMS than quagga mussels. While their adhesion strengths were similar on PVC, there were differences in the failure mode and the plaque-substrate interface ultrastructure. Comparisons with previous marine mussel studies demonstrated that freshwater mussels adhere with comparable strength despite known differences in protein composition. An improved understanding of freshwater mussel adhesion mechanics may help explain spreading dynamics and will be important in developing effective antifouling surfaces.

Variable changes in zooplankton phenology associated with the disappearance of the spring phytoplankton bloom in Lake Michigan

Abstract Changes in seasonal cycles (i.e., phenology), can cause mismatches throughout aquatic food webs and often are used as the primary indicator of zooplankton response to environmental changes. However, zooplankton phenology has been largely overlooked in Lake Michigan despite the altered phenology of phytoplankton, including the disappearance of the offshore spring phytoplankton bloom following Dreissena mussel invasions. Multiple measures of phenology were evaluated for the major zooplankton groups in offshore southeastern Lake Michigan both before the loss of the spring bloom (1983–2003), and after the spring bloom had disappeared (2007–2019). Water temperatures in spring did not differ between time periods. Standardised biomass declined between time periods for all zooplankton groups in spring and for total zooplankton and the cladoceran Daphnia in the summer. Changes in zooplankton phenology varied across groups and depended on the phenological measures used. Month of peak biomass shifted later for all groups, but the central point of the growing season did not change for any group between time periods. The onset of population development was delayed only for the copepod Limnocalanus. Spring chlorophyll concentrations combined with spring water temperatures provided the best predictions of population onset for Limnocalanus and Daphnia. The central point of the growing season varied with spring chlorophyll concentrations for Limnocalanus, but with spring water temperature for Daphnia. Changes in zooplankton phenology were relatively subtle compared to the large changes observed for spring chlorophyll concentrations. By contrast, there were fairly consistent declines in zooplankton biomass across groups that were associated with the declines in spring chlorophyll either alone or in combination with spring water temperature. This may mean that food limitation has a stronger influence on zooplankton biomass or production than on zooplankton phenology in offshore Lake Michigan. Based on our results from Lake Michigan, alterations such as nutrient reduction or invasive dreissenid mussel filtering that lead to declines in spring phytoplankton blooms in other large freshwater lakes could result in subtle delays in zooplankton phenology for some groups along with stronger declines in zooplankton biomass.

Impacts of native and invasive crayfish on three native and one invasive freshwater mussel species

Abstract Freshwater mussels and crayfish provide important ecosystem functions and services. In both groups, global declines of native species are paralleled by invasions of non‐native species. Knowledge on differences in predation susceptibility of native and invasive freshwater mussels exposed to native and invasive crayfish is essential for understanding their ecological interactions and for conservation management. In this study, we compared the predation impact of the native European noble crayfish (Astacus astacus) and the invasive signal crayfish (Pacifastacus leniusculus) on three native (Anodonta anatina, Anodonta cygnea, and Unio pictorum) and one invasive (Sinanodonta woodiana) mussel species in controlled laboratory experiments. We repeated the same experiments with the same crayfish specimens to investigate a potential learning effect of crayfish and assessed the in situ impacts in a natural stream. Mussel predation and damage caused by P. leniusculus was significantly higher than by A. astacus. Irrespective of the crayfish species, susceptibility was greater in native mussel species compared to invasive S. woodiana. Predation and damage was greatest in the thick‐shelled U. pictorum, suggesting that other factors such as shell shape are more important in explaining susceptibility than shell thickness. A predation learning effect from previous co‐exposure was evident, being most pronounced for A. astacus. Even if our experimental findings could not be confirmed in the field, the experimental results suggest that crayfish may have a negative impact on mussels and this impact will likely increase with the ongoing spread of P. leniusculus replacing A. astacus populations in Europe. The co‐occurrence of invasive P. leniusculus with the invasive S. woodiana could potentially exacerbate declines of endangered native mussel populations.

Invasion of Corbicula fluminea (Müller, 1774) (Bivalvia: Corbiculidae) in water bodies from the East Aegean River Basin in Bulgaria

Two decades after the first record of the invasive mussel Corbicula fluminea (Müller, 1774) in Bulgaria in 2001, it has been found in many surface lotic and standing waters in the Bulgarian Danube River Basin.
 The aim of the current study is to report the finding of C. fluminea in lotic environment of the East Aegean water basin in Bulgaria. Six new localities of the mussel, all situated in the lower stretches of the Tundzha (two) and Maritsa (four) River were registered. The distributional patterns of the mussel and the abundance of its populations in relation to the environmental conditions were analyzed. The adaptive character of the Corbicula, the possible path for invasion as well as the probability of rapid spread of the mussel in the largest rivers and their tributary systems in south-eastern part of Balkan Peninsula was discussed.

First Record of the Invasive Mussel Mytella strigata (Mollusca: Bivalvia: Mytilidae) in Panguil Bay, Southern Philippines

Here, we report the first record of the invasive mussel species Mytella strigata Hanley, 1843 in Panguil Bay, southern Philippines confirmed through its conchological features. Mussels appeared in dense mats attached to rocks, wood, and substrate in the intertidal region in the innermost portion of the bay. Locals first noticed the species in late 2018, which, according to them, adversely affected their catches of mangrove crabs Scylla spp. and the Asian hard clam Meretrix meretrix Linnaeus, 1758. There is a need to ascertain the distribution of the species within the bay, investigate socio-ecological and economic impacts, and formulate monitoring, surveillance, and impact mitigation measures.

Determining the post-herbivore-exclusion effect on an intertidal community by the recovery response of a known dominant herbivore

Following a long-term herbivore-exclusion study (2003-2008) in the mid-eulittoral zone at Kalk Bay, Cape Town, South Africa, the post-herbivore-exclusion effect (12 years later) of the limpet Cymbula oculus, the dominant herbivore in the community, was examined after it had recolonised the area. Despite the limpet having recruited into all plots (previous exclusion plots and control plots), the species richness, percentage cover of sessile organisms, invertebrate densities and invertebrate biomass were all significantly higher in previous exclusion plots compared with in control plots. Cymbula oculus density was higher in previous exclusion plots (11.11 [SD 12.54] ind. m−2) than in control plots (9.26 [SD 7.97] ind. m−2) (p = 0.038); however, its biomass was similar between the previous exclusion plots and control plots (366.39 [SD 421.63] vs 367.96 [SD 285.44] g m−2, p = 0.179), indicating that limpets outside exclusion plots were generally larger. This was likely because of younger C. oculus individuals, heightened interspecific competition, or insufficient space in previous exclusion plots. The observed differences might be attributed to a combination of factors, including the persistence of species that have achieved a size refuge from grazing and bulldozing by C. oculus, as well as the establishment of invasive mussels Mytilus galloprovincialis which offer secondary substrates and microhabitats for the establishment of macroalgae and other invertebrates. The recruitment of M. galloprovincialis into the previous exclusion plots is likely to be the cause of the alternative community state observed. Unless some extreme disturbance event occurs, the community from which C. oculus was previously excluded is unlikely to revert to its pre-C. oculus exclusion state.

An invasive mussel is in trouble: How do glyphosate, 2,4-D and its mixture affect Limnoperna fortunei's survival?

Contamination and biological invasions are important factors that alter the functioning of freshwater systems. We carried out two experiments involving daily measurements of dissolved oxygen (DO) and Limnoperna fortunei mortality: 1) the impact of DO on mussel survival mediated by glyphosate, 2,4-D and their mixture was analysed in a 22-day indoor experiment (IE) under controlled conditions using microcosms with L. fortunei, with and without air supply; and 2) the effect of each herbicide and their mixture on mussel accumulated mortality was compared in a 18-day outdoor experiment (OE) using mesocosms without air supply, with and without L. fortunei. Results showed that glyphosate, alone or mixed affected L. fortunei survival both directly and indirectly. In IE we observed direct toxicity of glyphosate in treatments with air supply, with accumulated mortality of 20.0% for glyphosate and 10.0% for the mixture. In OE, L. fortunei deepened the changes in the patterns of DO fluctuations driven by the herbicides, which led to hypoxia in the system. The accumulated mortality was 46.7, 8.6 and 48.2% for glyphosate, 2,4-D and the mixture, respectively. This study contributes to the understanding of the mechanisms that control the invasion of L. fortunei in freshwater systems influenced by agrochemicals.

Hitchhiking Exotic Clam: Dreissena polymorpha (Pallas, 1771) Transported via the Ornamental Plant Trade

Ornamental aquaculture is one of the main sources of non-native species worldwide. Unintentionally transported “hitchhiking” organisms have been previously recorded; although most of these species are transported from tropical regions, here we report on the first accidental transport of the zebra mussel (Dreissena polymorpha) in a shipment of ornamental Aegagropila linnaei (Chlorophyta) from Russia to the Czech Republic. This invasive mussel is listed on the national blacklist of alien species in the Czech Republic and can be easily released in outdoor garden ponds together with A. linnaei. Since the Czech Republic is known to be a gateway for aquatic ornamental species from a European perspective, re-export to other European countries is also possible. Thus, the spread of D. polymorpha via this pathway cannot be excluded. This finding should be of importance to conservationists, traders, decision-makers and other stakeholders.

Assessing Habitat Suitability for Native and Alien Freshwater Mussels in the River Waal (the Netherlands), Using Hydroacoustics and Species Sensitivity Distributions

Longitudinal training dams (LTDs) in the river Waal are novel river training structures that protect the littoral zone from the adverse effects of navigation providing new habitats for riverine macroinvertebrates. In order to inform river management and to better understand their ecological value for native and alien mussel species, it is important to assess the habitat suitability of the protected LTD shore channels. We applied spatial hydroacoustics surveys consisting of side-scan sonar (SSS) and acoustic Doppler current profiler (ADCP) of the substrate type, water depth and flow velocity in three shore channels in combination with species sensitivity distributions (SSDs) to predict habitat suitability for native and alien mussel species. SSDs allowed for the prediction of habitat suitability as a potentially occurring fraction (POF) of a species pool. High substrate type, water depth, and near-bottom flow velocity POFs were found for ≥ 70%, 100%, and 4–51% of the total shore channel area, respectively, suggesting that shore channels provide suitable habitat for both native and alien mussel species. To enhance the shore channels as habitat for native mussel species, we recommend increasing shallow areas dominated by fine (silt/clay) and sand substrate types with low near-bottom flow velocities (near 0 m/s). In contrast, the total area of hard substrate (e.g., boulders) in the shore channels should be reduced as it strongly favored invasive alien mussel species in our study. Future research should include additional abiotic parameters to enhance the habitat suitability predictions and compare the results for different riverine habitats.

A preliminary investigation of epibiotic macrofauna on the mangrove horseshoe crab Carcinoscorpius rotundicauda (Latreille, 1802) in Singapore

ABSTRACT Horseshoe crabs may act as mobile substrata for communities of sessile marine organisms on intertidal mudflats. In Singapore, the mangrove horseshoe crabs, Carcinoscorpius rotundicauda (Latreille, 1802) were surveyed for the diversity of epibiotic macrofauna. The most common epibiota observed was the barnacles belonging to Amphibalanus spp., along with other organisms: slipper snails Crepidula walshi and anemones (species undetermined). We also report the first account of an invasive American brackish mussel, Mytella strigata on C. rotundicauda in Singapore. Adult horseshoe crabs, particularly the males, have the highest prevalence and abundance of epibionts. A distinct distribution of epibionts was observed across horseshoe crab gender, age class and between the dorsal and ventral planes. Barnacles were found to be the dominant fouling on dorsal planes, while M. strigata and slipper snails occurred mainly on the ventral planes.

Prey utilization by Neptunea arthritica (Caenogastropoda: Buccinidae): predation on gastropods and size-related variation

ABSTRACT The whelk Neptunea arthritica (Buccinidae) is a common fishery species in Hokkaido, northern Japan. Although ecological information is needed for fisheries management, there is only one paper examining the foraging ecology of this species and it reported that N. arthritica preyed mainly on the invasive mussel Mytilus galloprovincialis. To date, no studies have examined utilization of native prey species by this whelk. Here, we report the findings of a study on the native prey utilization by N. arthritica in an area where M. galloprovincialis is not present. We conducted line transect sampling every month from May 2018 to May 2019 on the western coast of Hakodate Bay, southwestern Hokkaido, Japan. Prey items were composed mostly of gastropods (72%), followed by bivalves (24%) and only a small amount of carrion (<4%). Overlapping spatial distributions were observed among size classes of N. arthritica, while the prey utilization varied with body size. Small individuals (<30 mm in shell height) preyed mainly on the small colloniid gastropod Homalopoma sangarense, while larger individuals (>40 mm) preyed mainly on two tegulid gastropods (Chlorostoma lischkei and Omphalius rusticus) and two venerid bivalves (Protothaca euglypta and Ruditapes philippinarum). There were positive size relationships between whelk body size and prey size for prey categories (Vetigastropoda, Caenogastropoda and Bivalvia) and even for the same prey species (H. sangarense, O. rusticus and P. euglypta). These results suggest that N. arthritica is a predator of mobile gastropods, especially during its early life stage, in areas without the invasive Mediterranean mussel. It is possible that the foraging strategy of N. arthritica may differ quite markedly between areas with and without the invasive mussel.

Multiannual trends (2004–2019) in the abundance of larvae of the invasive mussel Limnoperna fortunei and crustacean zooplankton in a large South American reservoir

AbstractThe behavior of non‐indigenous species with time since introduction varies widely and is a major issue in the understanding of their long‐term effects on the habitats colonised. We analysed the long‐term trends in the densities of larvae of the invasive mussel Limnoperna fortunei and planktonic Copepoda and Cladocera in Salto Grande, a large South American reservoir in the Uruguay River (Argentina‐Uruguay), on the basis of weekly samples collected between June 2004 and November 2019. All three groups depicted variable interannual abundances. While mussel veligers showed no significant interannual trends (overall mean: 2552 larvae L−1), crustaceans decreased significantly in the time elapsed (Copepoda: from ˜1000 to 100 ind. L−1; Cladocera: from ˜500 to 100 ind. L−1). We conclude that increasing discharge rates by the Uruguay River and the concomitant decreases in reservoir water residence times are the most likely cause for these drops in their populations. As opposed to many other invasive species elsewhere, and to the same mussel in other South American waterbodies, L. fortunei larvae did not change in abundance with time since introduction. Our results underscore the assumption that each biological introduction is a particular and highly context‐dependent event and the dynamics of biological invasions in general elude broad generalizations.

A Case for the Continued Study of the Golden Mussel Invasion of Brazil: Efficient Detection and Containment of Limnoperna fortunei (Dunker, 1857) Dispersion Involves Multiple Approaches and Different Actors

A Case for the Continued Study of the Golden Mussel Invasion of Brazil: Efficient Detection and Containment of Limnoperna fortunei (Dunker, 1857) Dispersion Involves Multiple Approaches and Different Actors

Evidence for self-sustaining populations of Arcuatula senhousia in the UK and a review of this species\u2019 potential impacts within Europe

The invasive Asian date mussel (Arcuatula senhousia) inhabits diverse global coastal environments, in some circumstances posing significant ecological and economic risks. Recently recorded in the Greater North Sea ecoregion, an established population has not previously been confirmed. Combining historical and field data, we provided baseline information from the UK and recorded colonisation in a variety of habitats. Gonadal development was assessed using the gonadosomatic index (GSI) to determine if an intertidal soft-sediment population is self-sustaining. Arcuatula senhousia records from subtidal muddy/mixed-sediment within a major estuarine system from 2007 to 2016 were also analysed. First detected in 2011, spatial distribution was variable across the years within the subtidal, with individuals found at 4–9 out of 25 sites, and densities per site varying from 10 to 290 individuals per m2. The intertidal population was, in part, associated with seagrass (Zostera spp.) and attached to bivalves. In marinas, individuals were attached to concrete tiles, associated with live Mytilus edulis, and to dead Ostrea edulis. Mean GSI from the intertidal population differed across months, peaking in July before declining in September/October, but with high inter-individual variability. Arcuatula senhousia is reproducing and maintaining viable populations. Using a natural capital approach, we identify the potential impacts on Europe’s functionally important habitats, fisheries and aquaculture if its spread continues.

Biogeographic drivers of distribution and abundance in an alien ecosystem engineer: Transboundary range expansion, barriers to spread, and spatial structure

AbstractAimBiogeographic boundaries can act as either weak or strong barriers to the spread of species undergoing distributional change. Once a novel species spreads across a boundary, it can have a substantial impact on the ecosystem, for instance by competing with local species, and, over the long‐term, re‐engineer the ecosystem. Marine biogeographic regions are clearly defined on the coast of southern Africa and we tested the influence of their boundaries on the spread and spatial structure of an alien ecosystem engineer.LocationSouthern Africa.TaxonAn invasive mussel, Mytilus galloprovincialis.MethodsRecords of M. galloprovincialis were compiled into a database to determine its decadal patterns of spread across multiple bioregions. Distribution and abundance (estimated using density and semi‐quantitative abundance scale [ACFOR]) of this mussel were surveyed to determine patterns in spatial structure across bioregions. In addition, we compared the size structure of populations at the eastern margins of its range with those of larger populations nearer the range centre.ResultsInitial breaching of biogeographic boundaries was associated with rapid spread, but other boundaries encountered decades later acted as barriers to further spread. Across >2,800 km of coast, spatial autocorrelation was observed in densities (low and mid shore levels) and in ACFOR abundances. Repeating spatial patterns in densities and ACFOR abundance were detected at scales of 120–160 km and of 400–990 km. Considerable effort was required to detect populations at the absolute eastern limits of its distribution.Main conclusionDetection of spatial structures at multiple scales suggests that ecologically determined processes regulate abundance at both intra‐bioregional and inter‐bioregional scales, which may help tease apart the historic and contemporary consequences of interspecific interactions on the structure of rocky shore communities. This study demonstrates the influence of biogeography in driving temporal patterns of spread and spatial structure on the distribution and abundance of an invasive species.

Game-based learning for engaging citizens in biopollution control

ABSTRACT Citizens are essential for safeguarding ecosystems from biopollutants, but raising the population’s awareness of the problem through the communication of scientific discoveries about biological invasions is still a challenge. Here, we have assayed an interdisciplinary game-based method of recognizing the invasive pygmy mussel Xenosotrobus securis for volunteers of different age groups, we have measured their learning gain and engagement, and we have compared it with that obtained from conventional talk-lecture training. A highly significant positive correlation was found between knowledge gain and awareness, which were both greater in children than in adults. Similar engagement was achieved in the two age groups regarding volunteering in an eradication project. The results suggest the high efficacy of game-based training, especially in young age groups. One year after the volunteers’ action, environmental DNA surveys and visual inspections confirmed the control of the invasive species population in a defined area through time.

Dreissenids\u2019 breaking loose: differential attachment as a possible driver of the dominance shift between two invasive mussel species

Ponto-Caspian dreissenids are notorious freshwater invaders. Recently, widespread observations show a dominance shift from the early invader, Dreissena polymorpha, to its successor, Dreissena bugensis. These observations likely reflect congeneric species differences in physiological and behavioural traits. Here, we assessed the mussel attachment strength, attachment rate, and the mode of byssal failure as trait differences that could potentially contribute to dominance shifts. The attachment traits were measured in field and laboratory experiments. Fouling plates were deployed in the Rhine-Meuse river delta and dreissenids were collected and acclimatised in 60 L non-aerated freshwater tanks. Attachment strength was positively correlated with shell size. The attachment strength of D. bugensis was significantly greater compared to slower growing D. polymorpha individuals of a dreissenid field assemblage. This corresponded to the superior byssal thread morphology of D. bugensis (i.e. higher number and two times wider byssal threads). Moreover, our results indicated that byssal threads of D. bugensis are stronger than those of D. polymorpha, as the latter ruptured more often. Additionally, D. bugensis had a significantly lower attachment rate than D. polymorpha. Having a greater attachment strength gives D. bugensis an advantage when it comes to withstanding currents and predators. On the other hand, not being attached allows an individual to actively move around. This would allow them to move away from fast changing unfavourable environmental conditions. These attachment traits indicate competitive benefits for D. bugensis over D. polymorpha, therefore possibly contributing to the dominance shifts.

Macrofauna associated with intertidal mussel beds in the Knysna estuarine embayment, South Africa

The alien invasive mussel, Mytilus galloprovincialis, forms biogenic habitats in the embayment of Knysna Estuary. Invertebrate macrofauna inhabiting mussel beds were sampled from six sites in the embayment. In addition, mussel cover, mussel bed depth, density and size of mussels were recorded. With the exception of two sites (The Heads and Featherbed) where some Perna perna was present, we confirmed that the mussel beds were composed of the invasive species M. galloprovincialis. At The Heads, mussel beds were single-layered and in patches, whereas at other sites they were multi-layered with 100% cover. Bed depth, mussel density and shell size varied among sites. A total of 65 taxa (mainly Crustacea and Mollusca) were identified across all sites with species richness and diversity being significantly different among sites. Forty-three percent of taxa were new records for the estuary. Macrofaunal richness and diversity were highest at the two sites (The Heads and Featherbed) closest to the mouth of the embayment. There were negative relationships between species diversity and mussel density, and diversity and macroinvertebrate abundance. At most sites macrofaunal abundance was dominated by one or two species. Multivariate analysis revealed a significant difference in species composition among sites. Where wave action was present (The Heads, Featherbed and Leisure Isle) only a few deposit feeders were present in the mussel beds. At sites where wave action was minimal (Thesen Wharf, Marina and Railway Bridge) fine silt was present in the mussel matrix and there was an increase in the number of deposit feeding species.

Effect of airflow on overland transport potential of the invasive quagga mussel (Dreissena bugensis)

Effect of airflow on overland transport potential of the invasive quagga mussel (Dreissena bugensis)

Dreissenids’ need for speed: mobility as a driver of the dominance shift between two invasive Ponto-Caspian mussel species

Dreissenids’ need for speed: mobility as a driver of the dominance shift between two invasive Ponto-Caspian mussel species