Seasonal Occurrence Patterns Research Articles

Vocalization behaviors of minke whales in relation to sonar in the planned Undersea Warfare Training Range off Jacksonville, Florida

Nine Marine Autonomous Recording Units (MARU’s) were deployed in a rectangular array at a site coinciding with the United States (U.S.) Navy’s planned Undersea Warfare Training Range (USWTR) approximately 60–150 km offshore Jacksonville, FL (13 September to 8 October and 3 December to 8 January, 2009–2010) at shallow, mid-depth, and deep sites (45, 183, 305 m). Data were reviewed in detail using Triton (Wiggins, 2007). Event logs were created for each day at every site. Custom-written MATLAB scripts were used to calculate the probability of minke whale vocalization events occurring in the presence and in the absence of mid-frequency sonar. Minke whale vocalization events were completely absent in the fall deployment period, but occurred almost continuously during the winter deployment, indicating a strong seasonal pattern of occurrence. Minke whale vocalizations were detected most frequently at deep-water sites, and only at low levels (<0.03% of time) at shallow-water sites. Results of the probability analysis indicated a strong negative correlation to sonar. Minke whale vocalization events were greatly reduced, or completely ceased, during most days with nearly continuous sonar events during an approximate 3-day period. To our knowledge, such changes in acoustic behaviors of minke whales in relation to sonar have not been reported before.

Storage and origin of metals in active stream sediments from mountainous rivers: A case study in the River Douro basin (North Portugal)

The study area is located in the transboundary River Douro basin (northern Portugal); it comprises the River Corgo fluvial network, which drains a meso-scale rural catchment with an area of 295km2, underlain by crystalline rocks, in a temperate climate. The results reported in this study derive from a geochemical survey of active fluvial sediments, with the aim of characterising the spatial and temporal distribution of the contents of As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn in a basin with mountainous features. To assess total contents of metals and their potential availability, as well as possible different origins of metals (natural vs. anthropogenic), a sequential chemical approach was used (modified BCR procedure). Multivariate data analysis (PCA) was used to assist the interpretation of datasets.The results show that, on the one hand, the metal contents distribute among all the geochemical phases studied. For the most relative labile fractions the reducible fraction is the most significant. The element-partitioning among geochemical phases indicates: (a) Co and Mn are transported in greater proportions in the most labile fraction, as exchangeable ions, as well as important proportions of Ni, Zn and Cu; (b) Cd and Pb associate preferentially with the hydroxides of Fe and Mn; (c) Cr and Cu are also transported by the organic phase; (d) the residual phase transport important proportions of Cr, Ni, Zn, Cu, Fe and Pb. The higher concentrations of Cu, Zn and, in particular, Pb, in the most labile fractions, which are higher where the total contents are also higher (and not concomitant with a correspondent increase in the residual fraction), suggest an important contribution of anthropogenic activities to the total contents of these elements in the sediments. Chromium and Ni are the main metals from a lithological source, with relatively higher contents in the residual fraction, and the lowest in the most mobile fractions. On the other hand, the spatial distribution pattern of metal contents in the mobile and semi-mobile fractions (available+reducible+oxidisable), shows that, in general, higher contents of metals in the most mobile fractions occur along the main courses of the major tributaries, in particular in the flatter reaches. The patterns of seasonal occurrence and distribution of metals show, in general, that the relative contents associated with the potentially available fraction increase during the period of low flow, which extends from April to September.

On Incremental Incidence Rates in Long-Term Cohort Safety Studies

In long-term single cohort safety studies, the incremental incidence rate is a useful concept in evaluating risks related to adverse events of medical interest (EMI). We propose estimates for the incremental (say annual) incidence rates in the presence of independent random right censoring and describe their statistical properties. More importantly, we propose tests for the null hypothesis that the incremental incidence rates remain constant during the study against various alternative hypotheses, such as rates changing over the years or having a specific trend, say monotonic increasing or decreasing. In contrast with the existing methods that test constant hazard rates, the proposed method allows nonconstant hazard within each year; therefore, it is especially useful for EMIs that have a seasonal occurrence pattern. This article explores and characterizes properties of these tests under various alternatives via theory and simulations. A numerical example based on a real long-term single cohort safety study is also provided to demonstrate the application and interpretation of the proposed tests. It also illustrates limitations of visually inspecting the rates, as opposed to formally testing them, to assert a causal link between exposure and adverse EMIs.

Seasonal occurrence of mesopelagic fish larvae on the onshore side of the Kuroshio off southern Japan

Information on the annual reproductive cycle of mesopelagic fishes has been limited in the western North Pacific, despite their ecological importance. The Kuroshio region is an important spawning ground for various mesopelagic fishes. To describe the reproductive seasonality, we examined the seasonal occurrence patterns of mesopelagic fish larvae at a fixed station (33°12′N, 133°48′E) on the continental slope in Tosa Bay which is strongly influenced by the Kuroshio, based on monthly samples collected from January 2001 to December 2004. In total, 2558 mesopelagic fish larvae were sampled, with a peak abundance during May to June. Larvae of the dominant families Myctophidae, Sternoptychidae, Gonostomatidae, Bathylagidae, and Phosichthyidae were represented by 26 species (or types) belonging to 18 genera. The 12 most abundant species accounted for 96.9% of the total catch. The seasonal occurrence patterns of these larvae were categorized into five groups in accordance with the physical properties of the water column: Winter (Notoscopelus japonicus and Lipolagus ochotensis); Spring (Symbolophorus evermanni and Maurolicus japonicus); Early summer (Myctophum asperum and Diaphus stubby type); Autumn (Lampanyctus sp. A, Cyclothone spp., and Sigmops gracile); and -round (Vinciguerria nimbaria, Diaphus slender type, and Diogenichthys atlanticus) groups. No significant difference was observed in the months of peak abundances of these larvae during the 4 years, suggesting that each species has a fixed seasonal pattern of reproduction. The various patterns of seasonal occurrence would result in seasonal habitat segregation of the larvae among species, potentially enabling the reduction of intraspecific competition for food resources in the oligotrophic waters of the Kuroshio.

동해 중남부 해역 표층에서 출현하는 자치어의 계절분포

The seasonal distribution and abundance of larval fishes in the central and southern surface waters of the East Sea were investigated seasonally during 2011 and 2012. During the study period, the larvae of 39 species belonging to 26 families were collected. The most abundant species were Engraulisjaponicus, which accounted for 97.5% of the total number of individuals collected. Scomber japonicus, Clupea pallasii, Chromis notatus, Cottidae sp., and Coryphaena hippurus accounted for 1.7% of the total. The number of species, number of individuals, and species diversity indices fluctuated with the season. The peak number of species and individuals occurred in September and May, respectively. The larvae of the main species displayed a distinct spatial distribution and seasonal occurrence patterns. E. japonicus and C. notatus widely distributed throughout the study area. During summer and autumn, S. japonicus and C. hippurus were abundant in southern and offshore regions. C. pallasii occurred only in the southern region during winter. The seasonal occurrence and patterns of distribution of the larvae of main species seems were correlated with surface water temperature.

Seasonal occurrence patterns and the growth of Polyphylla albolineata in Fujisawa City, Kanagawa Prefecture, central Japan and the breeding under a room condition

Seasonal occurrence patterns and the growth of <i>Polyphylla albolineata</i> in Fujisawa City, Kanagawa Prefecture, central Japan and the breeding under a room condition

Interactive Influence of Temperature and Relative Humidity on Egg Parasitoids of &lt;I&gt;Riptortus pedestris&lt;/I&gt; (Hemiptera: Alydidae)

Previous studies reported that of the two egg parasitoids of Riptortus pedestris (F.) (Hemiptera: Alydidae) found in Korea, Gryon japonicum (Ashmead) (Hymenoptera: Scelionidae) appears in soybean fields much earlier than Ooencyrtus nezarae Ishii (Hymenoptera: Encyrtidae). To explain this phenomenon, we evaluated the interactive influence of temperature and relative humidity (RH) on the biological attributes of these parasitoids, including adult parasitoid longevity and survival. Temperature had significant effects on all the biological attributes examined for both parasitoids, while RH only affected rates of parasitism and adult emergence. Interaction between temperature and species, but not RH and species was found to affect significantly on parasitism. G. japonicum showed higher relative increment in parasitism than O. nezarae at temperatures higher than 25 degrees C. No significant differences in progeny sex ratio were detected for either species at any temperature x humidity combination. RH had no effect on the developmental time of O. nezarae but on the developmental time of G. japonicum, which was longer at low RH. Although the biological attributes of adult parasitoids of both species showed a wide range of adaptability, but it did not explain the patterns of occurrence of these species in the field. However, G. japonicum showed greater longevity than O. nezarae at all combinations of temperature and RH and this may partially explain the seasonal pattern of occurrence of adult parasitoids in the field previously observed.

Seasonal Dynamics in Plankton Abundance and Diversity of a Freshwater Body in Etche, Nigeria

Fluctuation in plankton abundance and diversity of the Imo River in Etche, a Niger Delta region of Nigeria was investigated. Plankton samples were collected with 55 micro meter mesh size plankton net at 7 sampling locations once monthly between March 2007 and February 2009. Samples were preserved with 4% formalin solution in labeled plastic containers in the field. In the laboratory, 1ml of the plankton subsample was withdrawn with a wide-mouthed pipette from field samples and placed on a Sedge-wick rafter-counting chamber for species identification and counts with standard keys through direct microscopy. The studentized t-test of significance was used to partition numerical abundances of plankton biotypes seasonally. Phytoplankton comprised 43 genera and a mean density of 1859 cells/ml. The dominant phytoplankton was the Bacillariophyceae (53.25%), followed in order by Cyanophyceae (21.25%), Chlorophyceae (10.33%), Chrysophyceae (4.84%), Pyrrophyceae (4.57%), Xanthophyceae (3.39%) and Euglenophyceae (2.42%). Zooplankton was made up of 7 taxa and a mean density of 433 organisms/ml. The order of dominance was the Cladocera (25.87%), Copepoda (20.55%), Protozoans (19.17%), Rotifera (18.71%), fish eggs and larvae (9.24%), Crab larvae (4.62%), and Beetle larvae (0.69%). Phytoplankton species showed oscillating as well as stable seasonal patterns of occurrence. Higher Margalef’s diversities were recorded in the dry (3.655; 57% and 1.273; 61%) than wet season (2.732; 43% and 0.810; 39%) for phytoplankton and zooplankton biotypes, respectively. Phyto- and zoo-plankton taxa each showed significant numerical differences between the 2007/2008 and 2008/2009 sampling periods [F(14.39)>Fcrit(4.30) and F(29.08)>Fcrit(4.23), respectively] at P<0.05. The observed seasonal peaking in abundance could be attributed to periods of concentrations of nutrients and stability in growth factors of plankton biotypes.

Spatial synchronies in the seasonal occurrence of larvae of oysters (Crassostrea gigas) and mussels (Mytilus edulis/galloprovincialis) in European coastal waters

Reproductive cycles of marine invertebrates with complex life histories are considered to be synchronized by water temperature and feeding conditions, which vary with season and latitude. This study analyses seasonal variation in the occurrence of oyster (Crassostrea gigas) and mussel (Mytilus edulis/galloprovincialis) larvae across European coastal waters at a synoptic scale (1000s of km) using standardised methods for sampling and molecular analyses.We tested a series of hypotheses to explain the observed seasonal patterns of occurrence of bivalve larvae at 12 European stations (located between 37°N and 60°N and 27°W and 18°E). These hypotheses included a model that stated that there was no synchronisation in seasonality of larval presence at all between the locations (null hypothesis), a model that assumed that there was one common seasonality pattern for all stations within Europe, and various models that supposed that the variation in seasonality could be grouped according to specific spatial scales (i.e., latitude, large marine ecosystems and ecoregions), taxonomic groups, or several combinations of these factors.For oysters, the best models explaining the presence/absence of larvae in European coastal waters were (1) the model that assumed one common seasonal pattern, and (2) the one that, in addition to this common pattern, assumed an enhanced probability of occurrence from south to north. The third best model for oysters, with less empirical support than the first two, stated that oysters reproduced later in the south than in the north. For mussels, the best models explaining the seasonality in occurrence of larvae were (1) the model that assumed four underlying trends related to large marine ecosystems, and (2) the one that assumed one common seasonal pattern for larvae occurrence throughout Europe.Such synchronies in larval occurrences suggest that environmental conditions relevant to bivalve larval survival are more or less similar at large spatial scales from 100s to 1000s of km. To unravel the underlying mechanisms for this synchronisation is of particular interest in the light of changing environmental conditions as the result of global climate change and the possible consequences for marine food webs and ecosystem services.

Effect of climate on malarial vector distribution in Monsoon Asia: coupled model for Ecophysiological and Climatological Distribution of mosquito generations (ECD-mg)

The relationship between the life cycle and climate conditions of the malaria vector mosquito Anopheles was modeled in order to describe its temporal and geographic distribution at a fine resolution. Since the mosquito grows through immature life stages in an aquatic environ- ment, the model was designed to express the surface moisture conditions conducive to the mos- quito's growth. The development of the mosquito was estimated using either air or water temper- ature, depending on the developmental stage of the mosquito's life cycle. To achieve this, the previous model was modified in order to improve the estimation of the water conditions of its habi- tat. As a result, the modified model was able to predict seasonal patterns of occurrence of Anophe- les at representative sites with a more reasonable degree of accuracy than the previous model. This model was then applied using simple climate data in order to obtain the geographic distrib- ution of the occurrence of various species of Anopheles in Monsoon Asia. The most notable results of the simulated spatio-temporal emergence of the Anopheles mosquito is that although the mod- ified model did not include unique parameters of each species, distribution was clearly divided into sub-regions for each dominant species that corresponded to the climate conditions.

Molecular epidemiology of human rhinovirus infections in Kilifi, coastal Kenya.

This study reports pediatric surveillance over 3 years for human rhinovirus (HRV) at the District Hospital of Kilifi, coastal Kenya. Nasopharyngeal samples were collected from children presenting at outpatient clinic with no signs of acute respiratory infection, or with signs of upper respiratory tract infection, and from children admitted to the hospital with lower respiratory tract infection. Samples were screened by real-time reverse transcriptase polymerase chain reaction (real-time RT-PCR) and classified further to species by nucleotide sequencing of the VP4/VP2 junction. Of 441 HRV positives by real-time RT-PCR, 332 were classified to species, with 47% (155) being HRV-A, 5% (18) HRV-B, and 48% (159) HRV-C. There was no clear seasonal pattern of occurrence for any species. The species were present in similar proportions in the inpatient and outpatient sample sets, and no significant association between species distribution and the severity of lower respiratory tract infection in the inpatients could be determined. HRV sequence analysis revealed multiple but separate clusters in circulation particularly for HRV-A and HRV-C. Most HRV-C clusters were distinct from reference sequences downloaded from GenBank. In contrast, most HRV-A and HRV-B sequences clustered with either known serotypes or strains from elsewhere within Africa and other regions of the world. This first molecular epidemiological study of HRV in the region defines species distribution in accord with reports from elsewhere in the world, shows considerable strain diversity and does not identify an association between any species and disease severity.

Annual pattern of occurrence of Riptortus pedestris (Hemiptera: Alydidae) and its egg parasitoids Ooencyrtus nezarae Ishii and Gryon japonicum (Ashmead) in Andong, Korea

Riptortus pedestris (Fabricius) (Hemiptera: Alydidae) is one of the major pests of soybean (Glycine max [L.] Merr.) in Korea and Japan. The occurrence of two important egg parasitoids of R. pedestris, Ooencyrtus nezarae Ishii (Hymenoptera: Encyrtidae) and Gryon japonicum (Ashmead) (Hymenoptera: Scelionidae), before and after soybean cultivation is poorly known. To record the seasonal occurrences of R. pedestris and parasitism during 2008–2010, aggregation pheromone traps baited with R. pedestris eggs were placed in a field in Andong, Korea where a series of crops, including barley (Hordeum vulgare L.), sesame (Sesamum indicum L.), and soybean, were cultivated during this study. R. pedestris was first recorded in the second week of April on barley and was most abundant in August on soybean. G. japonicum first appeared in May and was the dominant parasitoid until the first week of August on barley, sesame, and early soybean. From late August to September or October when soybean was cultivated, O. nezarae became the dominant parasitoid. The differential pattern of seasonal occurrence between the two parasitoids is discussed.

Structure and Composition of a Thrips Community in the Chihuahua Desert, New Mexico, U.S.

We examined plant used versus plant availability by a thysanopteran community on 13 woody and perennial native plants in the Chihuahua Desert. Individual plants were sampled with sticky-traps on 8 dates from May 1997 to August 1998. We sampled 5,040 adult thrips from 26 species in 19 genera, of which 16 could be identified to species. Four families were represented, Thripidae (17 species comprised 98.2 % of the collected specimens), Phlaeothripidae (5 species comprised 1.6%), Aeolothripidae (2 species comprised 0.1%) and Heterothripidae (1 species comprised 0.1%). A total of 16 species (84.2%) were phytophagous on flowers and leaves, 2 (10.5%) were predators, one (5.2%) was mycophagous. Feeding habits for 7 species are unknown. Thrips abundance was positively correlated with plant volume, but not with insect richness. Strikingly for a natural area, Frankliniella occidentalis accounted for 73.6% of the total collection of the sampled thrips, which together with Chirothrips falsus, Microcephalothrips abdominalis, Frankliniella gossypiana, and Neohydatothrips signifier, comprised 94.0% of the total number of collected thrips. Main abundances, considering all thrips species, occurred in fall and spring; no thrips were collected during winter. This seasonal pattern of occurrence was observed for the most abundant thrips species. In summary, the results of this study were: 1) few thrips species were found to be specialists; only 2 thrips species out of 12 studied, showed strong preference for host plants, 2) presence of a high percentage of positive associations, and a low percentage of negative associations, 3) the role of plant volume explained more than 80% of variance of thrips abundance. These results suggest that the studied thrips community has low plant specificity and the pattern of plant use observed could be the consequence of generalist feeding diets.

Marine megavertebrates of Cornwall and the Isles of Scilly: relative abundance and distribution

We document patterns of distribution and relative abundance of marine megavertebrate fauna around Cornwall and the Isles of Scilly from a combination of aerial and boat-based surveying. Between January 2006 and November 2007, 20 aerial surveys were undertaken, comprising over 40 hours of on-effort flying time. In April to October of these years, 27 effort-corrected ferry surveys were also conducted from a passenger ferry travelling between Cornwall and the Isles of Scilly. Opportunistic sightings were also logged by the crew members of the ferry and another vessel travelling regularly along the same route on 155 days. Ten megavertebrate species were sighted: basking sharksCetorhinus maximus, sunfishMola mola, common dolphinsDelphinus delphis, harbour porpoisePhocoena phocoena, grey sealsHalichoerus grypus, Risso's dolphinsGrampus griseus, bottlenose dolphinsTursiops truncatus, minke whalesBalaenoptera acutorostrata, long-finned pilot whalesGlobicephala melasand killer whaleOrcinus orca. During aerial surveys, 206 sighting events of seven species were made, compared with 145 sighting events of eight species during ferry surveys and 293 sighting events of 10 species from opportunistic ship-board data collection efforts. Seasonal and spatial patterns in species occurrence were evident. Basking sharks were the most commonly-sighted species in the region and were relatively abundant throughout the estimated 5 km-wide strip of coastal waters covered by the aerial surveys, during spring and summer. Ferry surveys and opportunistic vessel-based sightings data confirmed that the distribution of surface-feeding aggregations of this species was largely around the coasts. Despite the limited scope of this study, it has provided valuable baseline data, and possible insights into the marine biodiversity of the region.

Seasonal changes in seaweed deposition, seaweed fly abundance, and parasitism at the pupal stage along sandy beaches in central Japan

AbstractSeasonal relationships among stranded wrack quantity, seaweed fly abundances, and parasitism at the pupal stage were studied along three sandy beaches in central Japan. The seasonal occurrence patterns of puparia of seaweed flies Coelopa frigida and Fucellia spp. generally corresponded to seaweed deposition, which peaked in May–July and October–December. Parasitoids use fly puparia in these seasons. However, the occurrence of seaweed flies and their parasitoids varied among the three sandy beaches and did not correspond to the wrack amounts. These findings suggest that populations of seaweed flies and their parasitoids are seasonally, but not spatially, regulated by bottom‐up processes. The parasitoid assemblage of fly puparia was composed of two Aleochara (Coleoptera: Staphylinidae), two Trichopria (Hymenoptera: Diapriidae), and five pteromalid species (Hymenoptera), but the rate of parasitism was less than 20% and might have had little effect on fly populations.

Long-term coexistence of rotifer cryptic species.

Despite their high morphological similarity, cryptic species often coexist in aquatic habitats presenting a challenge in the framework of niche differentiation theory and coexistence mechanisms. Here we use a rotifer species complex inhabiting highly unpredictable and fluctuating salt lakes to gain insights into the mechanisms involved in stable coexistence in cryptic species. We combined molecular barcoding surveys of planktonic populations and paleogenetic analysis of diapausing eggs to reconstruct the current and historical coexistence dynamics of two highly morphologically similar rotifer species, B. plicatilis and B. manjavacas. In addition, we carried out laboratory experiments using clones isolated from eight lakes where both species coexist to explore their clonal growth responses to salinity, a challenging, highly variable and unpredictable condition in Mediterranean salt lakes. We show that both species have co-occurred in a stable way in one lake, with population fluctuations in which no species was permanently excluded. The seasonal occurrence patterns of the plankton in two lakes agree with laboratory experiments showing that both species differ in their optimal salinity. These results suggest that stable species coexistence is mediated by differential responses to salinity and its fluctuating regime. We discuss the role of fluctuating salinity and a persistent diapausing egg banks as a mechanism for species coexistence in accordance with the ‘storage effect’.

Bryde’s whale (Balaenoptera edeni) in the southwestern Gulf of California: Relationship with ENSO variability and prey availability

Interannual changes in the occurrence of Bryde’s whale (Balaenoptera edeni) have been observed in La Paz Bay (southwestern Gulf of California, Mexico) over the last 20 years. We suggest that these changes could be driven by natural fluctuations in food resources that are related to climate variability. We compared monthly Bryde’s whale occurrence in La Paz Bay from 1988 to 2006 to climate variability at seasonal and interannual time scales and its effect on prey availability. The results showed that Bryde’s whales do not have a well-defined pattern of seasonal occurrence; however, large numbers of whales were consistently recorded during La Niña conditions when the Gulf of California sardine population is distributed further south within the gulf. In contrast, fewer whales were recorded during El Niño and neutral conditions. This indicates that changes in the occurrence of Bryde’s whales at La Paz Bay are driven by the El Niño-Southern Oscillation interannual variability and are probably mediated by their prey availability.

Spatial and temporal patterns of occurrence of Lutzomyia sand fly species in an endemic area for cutaneous leishmaniasis in the Atlantic Forest region of northeast Brazil

Sand fly populations of different ecological niches in the Amaraji endemic American Cutaneous Leishmaniasis (ACL) focus of the Pernambuco Atlantic Forest region of northeastern Brazil were monitored spatiotemporally. Lutzomyia whitmani was dominant in all niches but occurred in smaller numbers in forested locations. L. whitmani was significantly less seasonal than the other species, being present throughout the year while other species were more abundant between February and April. These results suggest that L. whitmani may potentially be the principal vector of ACL in the region, even though the sand fly fauna was diverse: 88% were L.whitmani and 12% belonged to 11 other species. Two other species, L. complexa (1.3%) and L. migonei (0.8%), considered to be ACL vectors in other regions, were also present. This detailed picture of the sand fly population's abundance and spatiotemporal distribution provides a basis for future modeling studies of forecasting sand fly activity patterns and ACL occurrence.

Salmonella enteritidisInfection Complicated by Acute Myocarditis: A Case Report and Review of the Literature

Salmonella spp. is the cause of commonly encountered infections, with seasonal pattern of occurrence and worldwide distribution. Some of the clinical manifestations such as gastroenteritis and bacteremia are common, whereas others like mycotic aneurysms and osteomyelitis are infrequent especially in immunocompetent patients. Salmonella has been rarely described as a cause of myocarditis in the literature. We describe a case of an 18-year-old previously healthy male patient with myocarditis after Salmonella enteritidis infection. Clinical manifestations and diagnostic approach of this severe complication are discussed with a review of the literature.

Patterns of seasonal occurrence, distribution, and site fidelity of coastal bottlenose dolphins (Tursiops truncatus) in southern New Jersey, U.S.A.

AbstractCoastal bottlenose dolphins (Tursiops truncatus) form a mosaic of resident and seasonal migratory populations along the United States Atlantic seaboard. Seasonal, poorly known migrants (identified as a separate stock) move as far north as New Jersey. During 2003–2005, 73 boat‐based photo‐identification surveys were conducted in southern New Jersey to discern seasonal occurrence, distribution, and patterns of movement and site fidelity. Neonates, young‐of‐year, and adults occurred in the study area from late May through late September, corresponding to water temperatures of 14.0–16.3°C. Of 205 individuals identified, 44% (n= 90) were sighted multiple times within or among years, including 10% (n= 20) of individuals identified in all 3 yr. Almost half (47%) of the multiple sightings were observed along a core area encompassed by the southern part of the Jacques Cousteau National Estuarine Research Reserve. In contrast to stocks studied in southern coastal areas of the U.S. Atlantic and Gulf of Mexico, estuaries were used significantly less than open‐beach habitat, which is consistent with the relative prey abundance in these habitats. Research at additional sites will help confirm whether bottlenose dolphins at the northern end of their migratory range exhibit local site fidelity and habitat preferences similar to those found in this study.