Mussel Growth Research Articles

Condition and biochemical profile of blue mussels (Mytilus edulis L.) cultured at different depths in a cold water coastal environment

The growth and health of cultured blue mussels (Mytilus edulis) are affected by environmental conditions. Typically, culture sites are situated in sheltered areas near shore (i.e., <1km distance from land, <20m depth); however, land runoff, user conflicts and environmental impact in coastal areas are concerns and interest in developing deep water (>20m depth) mussel culture has been growing. This study evaluated the effect of culture depth on blue mussels in a cold water coastal environment (Newfoundland, Canada). Culture depth was examined over two years from September 2012 to September 2014; mussels from three shallow water (5m) and three deep water (15m) sites were compared for growth and biochemical composition; culture depths were compared for temperature and chlorophyll a. Differences between the two years examined were noted, possibly due to harsh winter conditions in the second year of the experiment. In both years shallow and deep water mussels presented similar condition; in year 2 deep water mussels had a significantly better biochemical profile. Lipid and glycogen analyses showed seasonal variations, but no significant differences between shallow and deep water were noted. Fatty acid profiles showed a significantly higher content of omega-3s (20:5ω3; EPA) and lower content of bacterial fatty acids in deep water sites in year 2. Everything considered, deep water appeared to provide a more favorable environment for mussel growth than shallow water under harsher weather conditions.

Within-river variation in growth and survival of juvenile freshwater pearl mussels assessed by in situ exposure methods

The early post-parasitic phase is considered to be the most vulnerable life stage of the endangered freshwater pearl mussel (Margaritifera margaritifera), yet little is known about the spatial variability in juvenile performance at a river scale. The main aim of this study was to determine within-river variation in habitat suitability for juvenile M. margaritifera. The growth and survival rates of juveniles (one and two year old) were measured in the Vltava River (Czech Republic) in relation to several physical and chemical variables using a total of 166 bioindication units (individual mesh cages and sandy boxes) during two thermally different vegetation seasons. Three spatial scales were studied: a longitudinal river profile, bottom habitat types, and hyporheic microhabitats. Both the survival rate and growth of the exposed juveniles varied considerably within the studied river. The effect of the longitudinal river profile and the roles of temperature, oxygenation within microhabitats, episodic pollution, and exposure method were demonstrated. This study represents the first example of a hierarchized approach to the assessment of a riverine mussel biotope with the use of bioindication methods. The results demonstrate the importance of the scale and bioindication method used in understanding the suitability of a river environment to juvenile freshwater mussels.

Freshwater nucleated pearl quality is influenced by host mussel growth traits in Hyriopsis cumingii

Freshwater nucleated pearl quality is influenced by host mussel growth traits in <i>Hyriopsis cumingii</i>

Population dynamics of subtidal blue mussels Mytilus edulis and the impact of cultivation

Fishery on subtidal mussel beds and subsequent relying on culture plots in the same system is a common practice in bottom mussel culture. We address factors that determine the population dynamics of subtidal blue mussels Mytilus edulis L. and to what extent total (natural plus cultured) subtidal mussel biomass in the system is affected by fishery practices. Mussel size and density of spatially segregated natural and cultured subtidal mussel populations in the western Wadden Sea were measured over time in 2 field studies. Spatial patterns in survival rates showed better spat survival in areas with lower salinity and lower density of sea stars Asterias rubens. This suggests that mussel survival is negatively related to sea star distribution which is to a large extent controlled by salinity. The Asterias−Mytilus relation in the Wadden Sea is an example of the concept that environmental stress determines the successes of the prey by affecting the prey− predator relationship. Natural beds that escape predation are found at lower salinities, and mussels on these beds showed low growth rates, also because of lower food quality in these areas. Mussel culture is strongly affecting the population dynamics of the subtidal mussel population, through relay of mussels from natural mussel beds to culture plots. This activity increases mussel growth and survival, because food quality on culture plots is high and predation is controlled. Despite harvesting, mussel biomass production on culture plots was higher than on natural mussel beds, enhancing total subtidal mussel stock.

Concrete deterioration caused by freshwater mussel Limnoperna fortunei fouling

Similar as biofouling of Dreissena species (zebra mussels and quagga mussels) on infrastructure concrete prevalent in the USA and Europe, the freshwater mollusk Limnoperna fortunei has also caused biofouling and exhibits chemical and physical deterioration on concrete structures. Given that numerous inter-basin water diversion projects containing enormous concrete structures have been constructed in L. fortunei colonized regions, it is critical to study the concrete deterioration caused by the mussel fouling such that effective prevention strategies can be proposed. This study analysed the characteristics of concrete deterioration associated with the fouling. Analysis of the affected concrete structures indicated that the pores of different sizes increased, resulting in increased water absorption and carbonation depth, while the compressive strength of the concrete decreased as a consequence of the mussel colonization. Concentrations of aluminum, manganese and iron increased while calcium decreased in the mussel-colonized concrete. These changes are due to the physiological requirements of mussel growth and adhesion activities. L. fortunei adhesion removes the calcium from the surface of the concrete and accelerates the concrete deterioration.

From classical to nonparametric growth models: Towards comprehensive modelling of mussel growth patterns

Understanding biological processes, such as growth, is crucial to development management and sustainability plans for bivalve populations. Von Bertalanffy and Gompertz models have been commonly used to fit bivalve growth. These models assume that individual growth is only determined by size, overlooking the effects of environmental and intrinsic conditions on growth patterns. The comparison between classical models and nonparametric GAM (generalized additive models) fits conducted in this work shows that the latter provide a more realistic approach of mussel growth measured in terms of shell length, and dry weight of hard and soft tissues. GAM fits detected a reduction in growth during the cold season, under unfavourable nutritional conditions. These fits also captured the decoupling between hard and soft tissue growth, widely addressed in the literature but not incorporated in growth models. In addition a GAM fit of condition index allowed us to explain annual changes in resources allocation, identifying the asymptotic growth of shell and the effects of the reproductive cycle on soft tissue fluctuations.

Effects of food resources on the fatty acid composition, growth and survival of freshwater mussels.

Increased nutrient and sediment loading in rivers have caused observable changes in algal community composition, and thereby, altered the quality and quantity of food resources available to native freshwater mussels. Our objective was to characterize the relationship between nutrient conditions and mussel food quality and examine the effects on fatty acid composition, growth and survival of juvenile mussels. Juvenile Lampsilis cardium and L. siliquoidea were deployed in cages for 28 d at four riverine and four lacustrine sites in the lower St. Croix River, Minnesota/Wisconsin, USA. Mussel foot tissue and food resources (four seston fractions and surficial sediment) were analyzed for quantitative fatty acid (FA) composition. Green algae were abundant in riverine sites, whereas cyanobacteria were most abundant in the lacustrine sites. Mussel survival was high (95%) for both species. Lampsilis cardium exhibited lower growth relative to L. siliquoidea (p <0.0001), but growth of L. cardium was not significantly different across sites (p = 0.13). In contrast, growth of L. siliquoidea was significantly greater at the most upstream riverine site compared to the lower three lacustrine sites (p = 0.002). In situ growth of Lampsilis siliquoidea was positively related to volatile solids (10 – 32 μm fraction), total phosphorus (<10 and 10 – 32 μm fractions), and select FA in the seston (docosapentaeonic acid, DPA, 22:5n3; 4,7,10,13,16-docosapentaenoic, 22:5n6; arachidonic acid, ARA, 20:4n6; and 24:0 in the <10 and 10 – 32 μm fractions). Our laboratory feeding experiment also indicated high accumulation ratios for 22:5n3, 22:5n6, and 20:4n6 in mussel tissue relative to supplied algal diet. In contrast, growth of L. siliquiodea was negatively related to nearly all FAs in the largest size fraction (i.e., >63 μm) of seston, including the bacterial FAs, and several of the FAs associated with sediments. Reduced mussel growth was observed in L. siliquoidea when the abundance of cyanobacteria exceeded 9% of the total phytoplankton biovolume. Areas dominated by cyanobacteria may not provide sufficient food quality to promote or sustain mussel growth.

Pemanfaatan tepung cangkang kijing taiwan untuk pertumbuhan kijing taiwan (Anodonta woodiana)

The purpuse of this research was to determine the effect of shell powder of Taiwanese mussel (Anodonta woodiana) at different doses on absolute growth, relative growth and survival rate of Taiwanese mussel. The treatment dosages of shell powder included A: 0 ppm, B: 10 ppm, C: 20 ppm, D: 30 ppm, and E: 40 ppm. Experimental design used was Complete Randomized Design with five treatments, each with three replications. The results showed that supplementation of 40 ppm of shell powder resulted in the best absolute growth and relative growth, namely 0.475 g and 1.84% respectively. Survival rate of Taiwanese mussel in all treatments during the experimental period was 100%. Keywords: Anodonta woodiana, Taiwanese mussel, shell powder, absolute growth, relative growth, survival rate

An improved method for in vitro culture of glochidia in freshwater mussel Cristaria plicata (Mollusca, Bivalvia)

We established an improved method for in vitro culture of glochidia in freshwater mussel Cristaria plicata and compared the transformation percentage in L-15 basic medium supplemented with different plasma from host fish or two non-host fish species. The results showed that the metamorphosis rate of glochidia cultured with host fish plasma and non-host fish plasma was all above 96%. High-density lipoprotein and low-density lipoprotein (LDL) levels were significantly lower in host fish plasma than in non-host fish plasma (P 0.05). The method developed herein not only provides a simplified in vitro culture method for glochidia at a reduced cost, but it also improves the culture efficiency. The method and medium composition may be further improved in studies investigating the long-term growth of juvenile mussels, and it would greatly benefit artificial breeding and germplasm resource preservation for this important species.

Nutrient and Chlorophyll &amp;lt;i&amp;gt;α&amp;lt;/i&amp;gt; Variability at a Micro-Scale Level in a Suspended Mussel Culture

Mussel farming by the long-line system, in the shallow waters of the NW Thessaloniki Gulf, Greece, is a vital economic activity for the local communities. The management practices play an important role both in the environmental quality and the support of the healthy growth of mussels. Αn experimental line of mussels in suspension placed at different sock distances as a management practice was systematically monitored for nutrients, chlorophyll α and dissolved oxygen. The study at four different mussel densities (distances of the socks) lasted from July 2014 to April 2015, covering the growth, reproduction and harvest cycle of mussels. Additional sampling took place in two selected sock distances, 30 and 70 cm, in the second sampling period, May-August 2015. The variability of nutrients along with chlorophyll α and dissolved oxygen, seasonally, spatially and vertically, was examined with the application of multivariate statistical analysis. The results showed low variation of nitrates among the sites but statistically significant differences of dissolved oxygen, ammonium, phosphate and chlorophyll α. The application of environmental indicators (TRIX, EI) in the data set was a useful tool in the identification of different variation schemes of the measured parameters in the cultures of various mussel densities.

Growth and Survival of Juvenile Freshwater Mussel, Chamberlainia hainesiana (Lea, 1856), at Three Densities in the Natural Reservoir and River Environments, Thailand

The effects of location and density on the growth and survival of juvenile freshwater pearl mussel, Chamberlainia hainesiana, 150–360 d after metamorphosis were investigated to determine the optimal ranges for commercial farming in Thailand. Juveniles were reared outdoors in two locations (the Mae Klong Reservoir and the Khwae Yai River, Kanchanaburi Province). Three density levels (25, 50, and 100 mussels/basket) were established at each location, with three replicates per density level. Phytoplankton from the water column in the natural habitats served as feed; no supplemental feed was provided. The mussels cultured in the reservoir had significantly higher growth rates than those cultured in the river (P 0.05), but both showed significant differences in growth from the density level of 100 mussels/basket (P < 0.01).

Features of growth for&lt;i&gt; Mytilus trossulus&lt;/i&gt; (Bivalvia: Mytilidae) in various conditions of habitat in the Tauiskaya Bay of the Okhotsk Sea

Biology of Mytilus trossulus is investigated in the Vesyolaya Cove, the Tauiskaya Bay on June 16 - September 20, 2011 within experimental studies of its cultivation ability in severe conditions of the northern Okhotsk Sea. In case of so called Spanish cultivation technology or its White Sea modification, the mussels grow to the commercial size (35 mm) in 3-4 seasons. To decrease this time to 1-2 seasons, the breeding technology is applied with the mussels collecting from the littoral substrate and their further breeding in hanged collectors. The mussels growth rate is evaluated both on the littoral substrate and in the collectors. The growth rate becomes lower after the mussels transfer from the littoral substrate to the hanged collectors but increases intensively after their transfer from the collectors to the littoral substrate, being higher that for the originally littoral mollusks. The growth rate dependence on size and age of the mussels is considered.

The forest and the trees: Small-scale ecological variability and archaeological interpretations of temporal changes in California mussel shell size

Abstract As global efforts to understand and document anthropogenic impacts on the coastal environment have increased, so have archaeologists' eagerness to contribute relevant research. Our publication ( Thakar et al., 2017 ) sought to enhance scientific rigor in archaeological evaluation of potential anthropogenic impacts on past shellfish communities through ecological assessment of small scale-variability in California mussel growth rates and through development of an alternative working hypothesis. In response to comment by Braje et al (2017) we offer additional explanation in support of our experimental design, targeted tidal foraging hypothesis, and methods of evaluation. We argue that in order to fully understand adaptations (or impacts) of prehistoric coastal foragers, archaeologists must embrace a nuanced view of how people dealt with small-scale ecological variability.

Effectiveness of a nonlethal method to quantify gamete production in freshwater mussels

AbstractStudies on the reproductive biology of freshwater mussels have contributed to conservation of this group, but methods to study early reproductive stages are either lethal (e.g., histological technique) or useful for only qualitative assessments (e.g., nonlethal syringe technique). Using 2 common mussels (Quadrula apiculata and Quadrula verrucosa) and 2 rare mussels (Quadrula petrina and Quadrula houstonensis) distributed across 3 sites in the Navasota River and San Saba River, Texas, we validated the effectiveness of the syringe technique to quantify gamete production by examining: 1) if estimates of gamete traits (sperm concentration, egg size, and egg concentration) obtained with the syringe technique were correlated to estimates of gamete traits (sperm density, egg size, and egg density) obtained with a histological technique; and 2) if survival, growth, and body condition of individual mussels sampled with the syringe technique were negatively affected in a 2-y mark–recapture field experiment....

Estimating the carrying capacity of green mussel cultivation by using net nutrient removal model

This study aims to evaluate the nutrient removal potential and carrying capacity of green mussel cultivation by using the mass balance model. The developed model takes into consideration the green mussel growth rate, density and chlorophyll a concentration. The data employed in this study were based on culture conditions at Sriracha Fisheries Research Station, Thailand. Results show that net nutrient removal by green mussel is 3302, 380, and 124mg/year/indv for carbon, nitrogen, and phosphorus respectively. The carrying capacity of green mussel cultivation was found to be 300indv/m2 based on chlorophyll a concentration which will not release phosphorus in the water environment beyond the standard (45μg-PO4−3-P/L). Higher chlorophyll a concentration results in lowered green mussel carrying capacity. This model can assist farm operators with possible management strategies for a sustainable mussel cultivation and protection of the marine environment.

Field-based experimental acidification alters fouling community structure and reduces diversity.

Increasing levels of CO2 in the atmosphere are affecting ocean chemistry, leading to increased acidification (i.e. decreased pH) and reductions in calcium carbonate saturation state. Many species are likely to respond to acidification, but the direction and magnitude of these responses will be based on interspecific and ontogenetic variation in physiology and the relative importance of calcification. Differential responses to ocean acidification (OA) among species will likely result in important changes in community structure and diversity. To characterize the potential impacts of OA on community composition and structure, we examined the response of a marine fouling community to experimental CO2 enrichment in field-deployed flow-through mesocosm systems. Acidification significantly altered the community structure by altering the relative abundance of species and reduced community variability, resulting in more homogenous biofouling communities from one experimental tile to the next both among and within the acidified mesocosms. Mussel (Mytilus trossulus) recruitment was reduced by over 30% in the elevated CO2 treatment compared to the ambient treatment by the end of the experiment. Strong differences in mussel cover (up to 40% lower in acidified conditions) developed over the second half of the 10-week experiment. Acidification did not appear to affect the mussel growth, as average mussel sizes were similar between treatments at the end of the experiment. Hydroid (Obelia dichotoma) cover was significantly reduced in the elevated CO2 treatment after 8weeks. Conversely, the percentage cover of bryozoan colonies (Mebranipora membranacea) was higher under acidified conditions with differences becoming apparent after 6weeks. Neither recruitment nor final size of barnacles (Balanus crenatus) was affected by acidification. By the end of the experiment, diversity was 41% lower in the acidified treatment relative to ambient conditions. Overall, our findings support the general expectation that OA will simplify marine communities by acting on important ecological processes that ultimately determine the community structure and diversity.

Growth-Prediction Model for Blue Mussels (Mytilus edulis) on Future Optimally Thinned Farm-Ropes in Great Belt (Denmark)

A recently developed BioEnergetic Growth (BEG) model for blue mussels (Mytilus edulis), valid for juvenile mussels, has been further developed to an ‘extended model’ and an alternative ‘ad hoc BEG model’ valid for post-metamorphic mussels, where the latter accounts for changing ambient chl a concentration. It was used to predict the growth of M. edulis on optimally thinned farm-ropes in Great Belt (Denmark), from newly settled post-metamorphic mussels of an initial shell size of 0.8 mm to marketable juvenile 30–35 mm ‘mini-mussels’. Such mussels will presumably in the near future be introduced as a new Danish, smaller-sized consumer product. Field data for actual growth (from Day 0 = 14 June 2011) showed that size of ‘mini-mussel’ was reached on Day 109 (Oct 1) and length 38 mm on Day 178 (Dec 9) while the corresponding predictions using the extended model were Day 121 (Oct 13) and Day 159 (Nov 20). Similar results were obtained by use of the ad hoc BEG model which also demonstrated the sensitivity of growth prediction to levels of chl a concentration, but less to temperature. The results suggest that it is possible (when the conditions are optimal, i.e., no intraspecific competition ensured by sufficient thinning) to produce ‘mini-mussels’ in Great Belt during one season, but not the usual marketable 45-mm mussels. We suggest that the prediction model may be used as a practical instrument to evaluate to what degree the actual growth of mussels on farm ropes due to intraspecific competition may deviate from the potential (optimal) growth under specified chl a and temperature conditions, and this implies that the effect of thinning to optimize the individual growth by eliminating intraspecific competition can be rationally evaluated.

Co-culturing green sea urchins (Strongylocentrotus droebachiensis) with mussels (Mytilus spp.) to control biofouling at an integrated multi-trophic aquaculture site

In a field study, five different stocking densities (i.e. 0, 30, 60, 90, 120ind.net−1 or 0, 2.46, 4.91, 7.37, 9.82ind.m−2) of adult green sea urchins (Strongylocentrotus droebachiensis) were randomly assigned to 30 predator-exclusion nets (i.e. n=6) around cultured mussels (Mytilus spp.) to test the effect of urchin density on biofouling intensity (percent net occlusion) and urchin/mussel growth. After 174days of culture, nets in all treatments containing sea urchins were significantly less fouled than those in the control treatment without urchins. Fouling intensities on nets with the two highest stocking densities of urchins (90 and 120ind.net−1) were approximately 40% less than that on nets with urchins held at the lowest stocking density (30ind.net−1) and 45% less than that on nets without urchins. The differences in fouling intensity among nets with 60, 90, and 120ind.net−1 were not statistically significant. While fouling was significantly reduced in the presence of urchins compared to the control treatment with no urchins, it was not completely eliminated since they were only able to access the inside surface of the nets. Sea urchin somatic and gonad growth declined with increasing stocking density, but there was no significant difference in mussel growth at the different urchin stocking densities. Mussels and sea urchins can be successfully co-cultured with no food input, but there may be a trade-off between the effectiveness of biofouling control and sea urchin growth. Statement of relevanceThis paper examined the use of sea urchins (Strongylocentrotus droebachiensis) to mitigate biofouling in mussel (Mytilus spp.) aquaculture and the effect of sea urchin density on biofouling coverage and mussel growth. Treatments containing sea urchins showed significantly less fouling than a control treatment without urchins. Urchin density had no significant effect on mussel growth.

Factors influencing the phosphorus distribution near the mouth of the Grand River, Ontario, Lake Erie

Abstract Phosphorus distribution in the nearshore of Lake Erie near the mouth of the Grand River, Ontario, reflects the extent of the mixing area between the river and the lake, with elevated concentrations observed directly within the river plume decreasing as the plume is mixed with the nearshore waters. Easterly alongshore currents were dominant within the area and affected the spatial distribution of phosphorus (P). Suspended solids concentration declined by an order of magnitude between the river and lake, and particulate P (PP) transitioned from being largely organic phosphorus and non-apatite inorganic phosphorus (NAIP) to predominantly NAIP only. Dominant processes transitioned from PP transport in suspension or resuspension in the river below Dunnville Dam to consumption and sedimentation in the lower reaches of the river and the nearshore. Higher dreissenid mussel density and mussel phosphorus content were at times associated with the mixing area of the Grand River, suggesting that river P influences the local ecology (e.g., Cladophora and mussel growth). Mussels and Cladophora in the study area are estimated to contain 8.6 and up to 4.9 tons of phosphorus in the standing biomass, respectively, which can be supplied by the Grand River in approximately 16–25 days.

Magnitude, spatial scale and optimization of ecosystem services from a nutrient extraction mussel farm in the eutrophic Skive Fjord, Denmark

Suspended mussel aquaculture has been proposed as a possible mechanism by which to remove excess nutrients from eutrophic marine areas. In this study, seasonal mussel growth and water clarification (through seston and phytoplank- ton depletion) were studied at a commercial-scale nutrient extractive mussel farm in a highly eu - trophic Danish fjord. Spatial variations in mussel biomass were examined throughout the year and no significant differences were detected within the farm. Food depletion by mussels was examined at spatial scales ranging from individuals to the entire farm and surrounding area. Phytoplankton deple- tion on the scale of individual mussel loops, deter- mined using the siphon mimic approach, indicated between 27 and 44% depletion of chlorophyll a (chl a). Farm-scale depletion was detected and visualized based on intensive 3D spatial surveys of the distribution of chl a and total suspended partic- ulate matter concentrations both inside and outside the farmed area. Average reductions in food supply within the farm ranged from 13 to 31%, with some areas showing > 50% food depletion. A food deple- tion model was developed to estimate the optimal mussel density required to maximize removal of excess phytoplankton. The model employed mus- sel clearance rate estimates derived from the ob - served magnitude of food depletion within the farm. Model results indicate that the mussel popu- lation filtration rate could be increased by 80 to 120% without any negative feedback on mussel growth. This could be accomplished by approxi- mately doubling the standing stock of mussels in the farm, hence doubling the amount of nutrients removed at mussel harvest.