Agri-environment schemes and butterflies: the utilisation of 6 m grass margins

The utilisation of 6 m countryside stewardship scheme (CSS) grass margins by butterflies was studied at two farms in Essex between 1997 and 2000. The aim of the study was to establish whether grass margins in cereal fields, as set up and managed under CSS guidelines, would be beneficial to common farmland butterflies. Eight 6 m grass margins (total length 3492 m) and two control sections (no margin; total length 700 m) were monitored over the first years of the agreements using the transect method. Significantly greater total numbers of butterflies and individuals of Maniola jurtina were seen on the 6 m grass margins than on the control sections. There was a significant increase in abundance of Maniola jurtina on the margins over the 4-year study period. Significantly more butterflies and Maniola jurtina were seen on the sown 6 m grass margin next to set-aside than on any of the other methods of establishment. Sown next to set-aside was best for Pyronia tithonus, but not significant.     

Grassland Butterfly Fauna under Traditional Animal Husbandry: Contrasts in Diversity in Mown Meadows and Grazed Pastures

Semi-natural grasslands resulting from traditional land use practices (mowing and grazing) are severely endangered throughout Europe due to the intensification of agriculture. The ecological impact of mowing and grazing on grassland butterflies was studied in eight mown meadows and eight grazed pastures under traditional animal husbandry in NW Russia and adjacent Finland. Transect count data over 3 years (1997–1999) covered a total of 48 species and 5742 individuals. The butterfly fauna was rather similar under both management forms; species richness, diversity and total abundance did not differ significantly between meadows and pastures, yet meadows were preferred by more species. In both groups, the most abundant species were Aphantopus hyperantus, Pieris napi and Thymelicus lineola. Of 37 species observed as a minimum of five individuals, Polyommatus amandus, Ochlodes sylvanus and A. hyperantus showed a significant preference for mowing management. According to the ordination, butterfly communities were affected more by the origin and age of the grassland than the present management method. Landscape factors (meadow or pasture surrounded by forests or open environments), the abundance of nectar plants and the intensity of tilling were the most important factors differentiating older grasslands from the younger ones evolved from old Finnish hay fields cultivated prior to the 1940s.     

Strongly diverging population genetic patterns of three skipper species: the role of habitat fragmentation and dispersal ability

The fragmentation of landscapes has an important impact on the conservation of biodiversity, and the genetic diversity is an important factor for a populations viability, influenced by the landscape structure. However, different species with differing ecological demands react rather different on the same landscape pattern. To address this feature, we studied three skipper species with differing habitat requirements (Lulworth Skipper Thymelicus acteon: a habitat specialist with low dispersal ability, Small Skipper Thymelicus sylvestris: a habitat generalist with low dispersal ability, Essex Skipper Thymelicus lineola: a habitat generalist with higher dispersal ability). We analysed 18 allozyme loci for 1,063 individuals in our western German study region with adjoining areas in Luxembourg and north-eastern France. The genetic diversity of all three species were intermediate in comparison with other butterfly species. The F _ST was relatively high for T. acteon (5.1%), low for T. sylvestris (1.6%) and not significant for T. lineola. Isolation by distance analyses revealed a significant correlation for T. sylvestris explaining 20.3% of its differentiation, but no such structure was found for the two other species. Most likely, the high dispersal ability of T. lineola in comparison with T. sylvestris leads to a more or less panmictic structure and hence impedes isolation by distance. On the other hand, the isolation of the populations of T. acteon seems to be so strict that the populations develop independently. Although no general genetic impoverishing was observed for the endangered T. acteon, small populations had significantly lower genetic diversities than big populations, and therefore the high degree of isolation among populations might threaten its local and regional survival.     

Abundance and size change of Hannaea baicalensis in Lake Baikal

Hannaea baicalensis is a benthic pennate diatom that predominantly grows at depths of less than a metre attached to rocks and filamentous algae in Lake Baikal, Russia. This narrow zone at the edge of the lake is subject to frequent wave action and lake level fluctuations, which combine with other factors to affect seasonal abundance. During ice cover from January to May in 2008, when lake levels decreased from 42 to 14 cm above datum, H. baicalensis cell abundance remained low (0.39 × 10⁶ cells cm^–2). The main period of net cell increase occurred in autumn, when there was a period of stable lake level (±10 cm changes in water depth) that coincided with the return of nutrients during autumn overturn. Cell abundance reached 1.52 × 10⁶ cells cm^–2 on 31 October. Alongside the changes in abundance, cyclic size changes in cell apical lengths were found (40 to 144 µm), which were associated with timing of the length of the life cycle. Size decline occurred in both spring and autumn, with an average decrease in apical length of 36 µm per year. It took two years for the mean apical length of a single cohort to decrease from 128 µm to 56 µm, which was then below the threshold (< 65 µm) for initiation of size regeneration.     

Quality of citizen science data and its consequences for the conservation of skipper butterflies (Hesperiidae) in Flanders (northern Belgium)

Citizen science projects have become important data sources for ecologists. However, opportunistic data are not only characterized by spatial and temporal biases, but probably also contain species identification errors, especially concerning morphologically similar species. Such misidentifications may result in wrongly estimated distribution ranges and trends, and thus in inadequate conservation measures. We illustrate this issue with three skipper butterflies (Hesperiidae) in Flanders (northern Belgium) using photographs uploaded with observations in data portals. Ochlodes sylvanus and Thymelicus lineola records had relatively low identification error rates (1 and 11?%, respectively), but the majority (59?%) of Thymelicus sylvestris records turned out to be misidentified. Using verified records only allowed us to model their distribution more accurately, especially for T. sylvestris whose actual distribution area had hitherto been strongly overestimated. An additional field study on T. sylvestris confirmed the species distribution model output as the species was almost completely restricted to sites with verified records and was largely absent from sites with unverified records. The preference of T. sylvestris for unimproved grasslands was confirmed by the negative correlation between its model-predicted presence and elevated nitrogen and ammonia levels. Thus, quality control of citizen science data is of major importance to improve the knowledge of species distribution ranges, biotope preferences and other limiting factors. This, in turn, will help to better assess species conservation statuses and to suggest more appropriate management and mitigation measures.     

Effects of the El Niño southern oscillation on Turbo torquatus (Gastropoda) and their kelp habitat

Abstract Turbo torquatus (hereafter Turbo) were abundant and patchily distributed, especially in algal dominated habitats in shallow water (less then 10 metres) on rocky reefs in central New South Wales, Australia. Although the assemblage of algae was similar in barrens with and without crevices, Turbo were most abundant in crevices, suggesting that shelter was important. Experimental removal of the kelp canopy resulted in a great decrease in the number of Turbo. This was despite cleared patches containing more filamentous food algae, further highlighting the importance of shelter. The density of Turbo in kelp forests ranged from six to seven per square metre in times of abundance and less then one per square metre at other times over a 12‐year period. Variation in the resource base (i.e. food algae and kelp cover) was strongly linked to the abundance of Turbo. Abundance of Turbo was lowest when the density of adult kelp was low (less than 14 plants per square metre). The condition of kelp was severely affected during the 1997–1998 and 2002 El Niño events and was compromised 2–4 years after each event. These pulse events and related loss of shelter probably contributed to a decline in abundance of Turbo. This model was further supported when Turbo abundance increased with a subsequent increase in the density of kelp.     

Evidence for host race formation in the leaf beetle Galerucella lineola

We examined preference and performance of four Finnish Galerucella lineola F. populations on alder and willow. In standardized two‐choice laboratory feeding trials with alder and willow, only two naturally alder‐associated G. lineola populations accepted alder. Two conspecific willow‐associated populations preferred willow. These preferences seem to be unstable, however, because they can be modified by the beetles’ experience. Thus, there probably is not a complete host preference‐based isolation of alder‐ and willow‐associated G. lineola beetles in nature. In performance experiments, larvae of all four populations survived better on willow than on alder. This may indicate that willows are the ancestral hosts for G. lineola. Nevertheless, larvae of the two alder‐associated G. lineola populations survived better on alder than larvae of the two willow‐associated populations. On the other hand, larvae of the two willow‐associated populations survived better on willow than larvae of the two alder‐associated populations. This performance trade‐off suggests that G. lineola encounters different selective pressures on alders and willows. On both of them, selection probably disfavours those G. lineola genotypes that are the most successful and abundant on alternative hosts. This may reduce the effects of gene flow that is likely to occur as a consequence of incomplete host preference‐based isolation of alder‐ and willow‐associated G. lineola populations. Data from pupal weights support the idea that alder‐ and willow‐associated G. lineola populations may be genetically differentiated. Pupae of the two alder‐associated populations were heavier than those of the willow‐associated populations irrespective of whether larvae had fed on alder or on willow. Overall, our results indicate host race formation in G. lineola. This process may be enforced by the variable abundance of alders and willows in local communities.     

Post hibernation dispersal of three leaf-eating beetles (Coleoptera: Chrysomelidae) colonising cultivated willows and poplars

1 We studied the spring dispersal of three common chrysomelids, from overwintering habitats into cultivated willow and poplar coppices at four sites in southern England over 2 years. 2 Adult Galerucella lineola, Phratora vulgatissima and P. vitellinae overwintered under the bark of mature trees or in other niches that simulated this habitat, within a few hundred metres of the coppice plantation. Relatively few beetles remained in the coppice fields during the winter. 3 Phratora vitellinae at the poplar sites emerged several weeks later than G. lineola and P. vulgatissima at the willow sites, reflecting the later leafing of poplar compared to willow. For all species, dispersal was by flight, with most activity during warm periods. Dispersal continued for several weeks for the willow- feeding species but was shorter for P. vitellinae. 4 All three species initially colonized the edge of the coppice field. Typically, 80% or more of the beetles colonising a plantation were within 8 m of the edge. Both Phratora spp. accumulated in the plantation edge zone for several weeks before leaving this area and colonising the crop interior. 5 The patterns of dispersal and colonization identified by this study may facilitate chrysomelid management practices in infested short rotation coppice that avoid the need for insecticide applications over the entire plantation. Keywords Chrysomelidae, Galerucella lineola, Phratora vitellinae, Phratora vulgatissima, poplar, short rotation coppice, willow, winter dispersal.     

Seasonal diapause development and diapause termination in the European skipper, Thymelicus lineola (Ochs.)

Eggs of the European skipper, Thymelicus lineola, containing pharate first-instar larvae were brought into the laboratory at the beginning of each month from September to May and maintained at 20°C, 14L:10D. No emergence was observed within 40 days of collection before December. From that time on, while total emergence was similar, the duration of the emergence period decreased over the season from > 120 days in December to < 14 days in May. There was however no marked change in the seasonal supercooling point values of diapausing larvae.The rate of emergence from eggs collected in March was influenced by photoperiod, being slower under short-day conditions. However for any given photoperiod tested, the rate of emergence increased with an increase in temperature. The possible adaptive significance of a two-phase diapause, where diapause termination is photoperiodically controlled in species that overwinter as an egg or as a pharate first-instar larva within the egg chorion in exposed habitats, is discussed.     

Use of field margins managed under an agri-environment scheme by foraging Barn Swallows Hirundo rustica

Capsule: Barn Swallows Hirundo rustica were more likely to forage along arable field margins that were enhanced with wildflowers or legumes than control grass margins.

Aims: To determine if foraging Barn Swallows displayed preferences for specific arable field boundary habitats (grass margins versus floristically enhanced margins) that were managed as part of an agri-environment scheme. We also aim to determine how Barn Swallow food abundance related to these habitats.

Methods: Two foraging activity surveys took place on all grass and floristically enhanced margins (n?=?56) present within the 600 m foraging range of seven Barn Swallow colonies during June and July 2016. Margin habitat use was measured by recording the presence/absence of foraging individuals during surveys, the total number of individuals and by calculating an index of foraging activity. Habitat information relating to adjacent boundary type, transect crop type and neighbouring crop type were also recorded.

Results: Foraging Barn Swallows were significantly more likely to be recorded when survey transects included a floristically enhanced margin, but there was no significant impact of floristically enhanced margins on the total number of individuals recorded or on the index of foraging activity. Foraging activity was higher along grass verges and hedgerows when compared to treelines and was positively related to length weighted Diptera abundance (a measure of food biomass).

Conclusion: Our results suggest that there may be a role for floristically enhanced margins in the conservation of Barn Swallows on arable farmland. More research, however, is needed to determine whether invertebrate-rich agri-environment scheme habitats can influence colony size or improve the breeding success of this species.     

Influences of blackberry margins on population dynamics of Drosophila suzukii and grape infestation in adjacent vineyards

Understanding the dynamics of pest insect populations in relation to the presence of non‐crop habitats and infestation levels of adjacent crops is essential to develop sustainable pest management strategies. The invasive pest species Drosophila suzukii (Diptera: Drosophilidae) is able to utilize a broad range of host plants. In viticulture, scientific risk assessment for D. suzukii has only recently started and studies assessing the effects of field margins containing wild host plants on D. suzukii population dynamics and on infestation risks in adjacent vineyards are lacking. Thus, in a one‐year field study, the role of different field margins on fly abundance and crop infestation in adjacent vineyards of Vitis vinifera, variety “Pinot Noir,” were investigated. Different monitoring methods were conducted to assess fly distribution, sex ratio and grape infestation in 14 vineyards adjacent to field margins containing either blackberry (BB) Rubus spp. or non‐host (NH) plants. Our results show that blackberries strongly enhanced D. suzukii abundance within field margin vegetation all year long, whereas fly abundance in vineyards adjacent to BB margins was just enhanced in some seasonal periods. Moreover, the influence of BB margins was limited by distance. However, high fly numbers in BB field margins did result in zero egg infestation of “Pinot Noir” berries. These results may have important implications for winegrowers to make efficient management decisions: regardless of high abundance of adult D. suzukii, only grape berry monitoring can assess the actual infestation risk and the potential need to take management action.     

Impacts of climate warming and habitat loss on extinctions at species' low-latitude range boundaries

Polewards expansions of species' distributions have been attributed to climate warming, but evidence for climate‐driven local extinctions at warm (low latitude/elevation) boundaries is equivocal. We surveyed the four species of butterflies that reach their southern limits in Britain. We visited 421 sites where the species had been recorded previously to determine whether recent extinctions were primarily due to climate or habitat changes. Coenonympha tullia had become extinct at 52% of study sites and all losses were associated with habitat degradation. Aricia artaxerxes was extinct from 50% of sites, with approximately one‐third to half of extinctions associated with climate‐related factors and the remainder with habitat loss. For Erebia aethiops (extinct from 24% of sites), approximately a quarter of the extinctions were associated with habitat and three‐quarters with climate. For Erebia epiphron, extinctions (37% of sites) were attributed mainly to climate with almost no habitat effects. For the three species affected by climate, range boundaries retracted 70–100 km northwards (A. artaxerxes, E. aethiops) and 130–150 m uphill (E. epiphron) in the sample of sites analysed. These shifts are consistent with estimated latitudinal and elevational temperature shifts of 88 km northwards and 98 m uphill over the 19‐year study period. These results suggest that the southern/warm range margins of some species are as sensitive to climate change as are northern/cool margins. Our data indicate that climate warming has been of comparable importance to habitat loss in driving local extinctions of northern species over the past few decades; future climate warming is likely to jeopardize the long‐term survival of many northern and mountain species.     

Will Environmental Stewardship enhance small mammal abundance on intensively managed farmland?

• 1 The creation of grassy field margins, as part of the UK Government's Environmental Stewardship (ES) scheme, is one of a number of measures proposed to mitigate the adverse effects of arable intensification on wildlife. Widespread development of these margins will potentially increase the amount of habitat available to small mammals in arable landscapes, as many species do not inhabit the cropped area.
• 2 The aim of this study was to determine what impact ES-type margins might have on small mammals. We compared small mammal abundance and biomass in spring and autumn on 3-m-wide and 6-m-wide grassy margins with that on conventionally managed field edges that have no margin (0 m wide) and are intensively cultivated to the field edge.
• 3 Bank voles Clethrionomys glareolus, wood mice Apodemus sylvaticus and common shrews Sorex araneus were the most abundant species; few field voles Microtus agrestis were captured on any margin. In autumn, bank vole and common shrew numbers were higher on the grassy margins than on conventional field edges, and margin width per se was positively associated with bank vole abundance. The number of wood mice captured did not differ among the different margin types.
• 4 Total small mammal biomass increased between spring and autumn on the 3-m- and 6-m-wide grassy margins, but decreased on the 0-m-wide margins. Total biomass in autumn was three times higher on 6-m-wide margins compared with the conventional arable field edges.

     

A baculovirus of the European skipper, Thymelicus lineola (Lepidoptera: Hesperiidae)

The nuclear polyhedrosis virus (NPV) of the European skipper, Thymelicus lineola, observed for the first time in Quebec in 1974, is highly pathogenic for its host. The infected larvae fill with pure polyhedra and die within 4 to 10 days. All tissues were infected except nerve cells and silk glands, but all nuclei of infected cells were filled with polyhedra. Biochemical analyses revealed that important metabolic disturbances occurred in infected larvae, such as serious modifications in the activity of certain enzymes. Polyhedra measured from 350 to 1330 nm in diameter and contained up to about 80 single-enveloped virions which measured to 270 × 58 nm. Abnormally short and abnormally long particles were also observed. Safety tests on mammals, fish, and beneficial insects revealed that this virus had no effect on these organisms, thus, it was recommended for the control of T. lineola outbreaks.     

Temporal variation in responses of species to four decades of climate warming

Many species are expanding at their leading‐edge range boundaries in response to climate warming. Species are known to respond individualistically to climate change, but there has been little consideration of whether responses are consistent over time. We compared responses of 37 southerly distributed British butterflies over two study periods, first between 1970–1982 and 1995–1999 and then between 1995–1999 and 2005–2009, when mean annual temperature increased regionally by 0.03 °C yr^?1 (a significant rate of increase) and 0.01 °C yr^?1(a nonsignificant increase) respectively. Our study species might be expected to benefit from climate warming. We measured three responses to climate to investigate this; changes in range margin, distribution area and abundance. In general, the responses of species were inconsistent over time. Species that increased their distribution areas during the first period tended to do so again during the second period, but the relationship was weak. Changes in range margins and abundance were not consistent. In addition, only 5/37 species showed qualitatively similar responses in all three response variables over time (three species increased and two species declined in all variables in both periods). Overall rates of range expansion and distribution area change were significantly greater in the second study period, despite the lower rate of warming, perhaps due to species exploiting climate‐distribution lags remaining from the earlier, warmer period. However, there was a significantly greater decline in abundance during the second study period, so range expansions northwards were not necessarily accompanied by increases in distribution area and/or abundance. Hence, species ranges have been thinning as they have expanded northwards. The idiosyncratic responses of these species likely reflect the balance of climatic and habitat drivers of species distribution and abundance changes.     

The influence of pre‐settlement and early post‐settlement processes on the adult distribution and relative dominance of two invasive mussel species

相似文献   

Does the presence of grassy strips and landscape grain affect the spatial distribution of aphids and their carabid predators?

• 1 We investigated, over the course of 2 years, the spatial distribution and abundance of two species of aphid, Metopolophium dirhodum and Sitobion avenae, and predatory species of carabid. This was undertaken in 24 wheat fields in ‘coarse‐grain’ and ‘fine‐grain’ landscapes in western France. A greater percentage of the latter landscape was covered by hedgerows and grassland and the total area covered by fields and the average size of the fields were smaller.
• 2 The effects on aphid abundance of the distance from field margins, the presence of grassy strips and carabid abundance were determined in both landscapes.
• 3 Both aphid species were more abundant in the ‘fine‐grain’ landscape, which may have been a result of the higher density of semi‐natural elements. In both types of landscape, the total numbers of aphids were negatively correlated with the distance from the field margin. This may have been because aphids were dispersing from overwintering sites in field margins. The abundance of M. dirhodum was strongly negatively correlated with the presence of grassy strips in the ‘coarse‐grain’ landscape, although there were no such significant correlations for either of the aphid species in the ‘fine‐grain’ landscape.
• 4 Aphid and carabid abundances were negatively correlated in the ‘fine‐grain’ and positively in ‘coarse‐grain’ landscape.
• 5 The results obtained in the present study emphasize the importance of semi‐natural areas in agricultural landscapes in shaping the spatial distribution of aphids and carabid beetles, their natural enemies, at different spatial scales.

     

Rewiring of interactions in a changing environment: nettle-feeding butterflies and their parasitoids

Climate and land use change can alter the incidence and strength of biotic interactions, with important effects on the distribution, abundance and function of species. To assess the importance of these effects and their dynamics, studies quantifying how biotic interactions change in space and time are needed. We studied interactions between nettle-feeding butterflies and their shared natural enemies (parasitoids) locally and across 500 km latitudinal gradient in Sweden. We also examined the potential impact of the range-expansion of the butterfly Araschnia levana on resident butterflies via shared parasitoids, by studying how parasitism in resident butterflies covaries with the presence or absence of the newly-established species. We collected 6777 larvae of four nettle-feeding butterfly species (Aglais urticae, Aglais io, Ar. levana and Vanessa atalanta), over two years, at 19 sites distributed along the gradient. We documented the parasitoid complex for each butterfly species and measured their overlap, and analysed how parasitism rates were affected by butterfly species assemblage, variations in abundance, time, and the arrival of Ar. levana. Parasitoids caused high mortality, with substantial overlap in the complex of parasitoids associated with the four host butterflies. Levels of parasitism differed significantly among butterflies and were influenced by the local butterfly species assemblage. Our results also suggest that parasitism in resident butterflies is elevated at sites where Ar. levana has been established for a longer period. In our study system, variations in butterfly species assemblages were associated in a predictable way with substantial variations in rates of parasitism. This relationship is likely to affect the dynamics of the butterfly host species, and potentially cascade to the larger number of species with which they interact. These results highlight the importance of indirect interactions and their potential to reorganise ecological communities, especially in the context of shifts in species distributions in a warmer world.     

Adult diet affects lifespan and reproduction of the fruit‐feeding butterfly Charaxes fulvescens

Fruit‐feeding butterflies are among the longest lived Lepidoptera. While the use of pollen‐derived amino acids by Heliconius butterflies has been interpreted as important for the evolution of extended lifespans, very little is known about the life‐history consequences of frugivory. This issue is addressed by investigating effects of four adult diets (sugar, sugar with amino acids, banana, and moistened banana) on lifespan and reproduction in the fruit‐feeding butterfly Charaxes fulvescens Aurivillius (Lepidoptera: Nymphalidae). Female butterflies were collected from Kibale National Park, Uganda, and kept individually in cages near their natural habitat and data were collected on lifespan, oviposition, and hatching of eggs. Lifespan in captivity was longer for the sugar and the amino acid cohort, than for the banana cohorts. The longitudinal pattern of oviposition was erratic, with many days without oviposition and few periods with high numbers of eggs laid. Butterflies typically did not lay eggs during their 1st week in captivity and the length of the period between capture and first reproduction was significantly shorter for butterflies fed moistened banana. The length of the reproduction period (first reproduction–last reproduction in captivity) and the reproduction rate (total number of eggs/length of the reproduction period) did not differ significantly between the diet treatments. Those fed with amino acid and moistened banana had significantly higher egg hatchability than those fed with sugar and banana. We found no evidence for a lifespan cost of reproduction. Our results show that (1) female C. fulvescens can use amino acids in their diet for laying fertile eggs, (2) more wing‐wear does correlate with lower survival in captivity (indicating aging in the wild), but not with intensity of reproduction (providing no evidence for reproductive aging), and (3) fruit‐feeding butterflies may be dietary restricted in the field.     

It’s a wormy world: Meta‐analysis reveals several decades of change in the global abundance of the parasitic nematodes Anisakis spp. and Pseudoterranova spp. in marine fishes and invertebrates

The Anthropocene has brought substantial change to ocean ecosystems, but whether this age will bring more or less marine disease is unknown. In recent years, the accelerating tempo of epizootic and zoonotic disease events has made it seem as if disease is on the rise. Is this apparent increase in disease due to increased observation and sampling effort, or to an actual rise in the abundance of parasites and pathogens? We examined the literature to track long‐term change in the abundance of two parasitic nematode genera with zoonotic potential: Anisakis spp. and Pseudoterranova spp. These anisakid nematodes cause the disease anisakidosis and are transmitted to humans in undercooked and raw marine seafood. A total of 123 papers published between 1967 and 2017 met our criteria for inclusion, from which we extracted 755 host–parasite–location–year combinations. Of these, 69.7% concerned Anisakis spp. and 30.3% focused on Pseudoterranova spp. Meta‐regression revealed an increase in Anisakis spp. abundance (average number of worms/fish) over a 53 year period from 1962 to 2015 and no significant change in Pseudoterranova spp. abundance over a 37 year period from 1978 to 2015. Standardizing changes to the period of 1978–2015, so that results are comparable between genera, we detected a significant 283‐fold increase in Anisakis spp. abundance and no change in the abundance of Pseudoterranova spp. This increase in Anisakis spp. abundance may have implications for human health, marine mammal health, and fisheries profitability.