Investigating the Functional Role of an Artificial Reef Within an Estuarine Seascape: a Case Study of Yellowfin Bream (<Emphasis Type="Italic">Acanthopagrus australis</Emphasis>)

Estuaries contain mosaic habitats which support fish across different life stages. Artificial reefs represent a form of habitat enhancement which can provide additional structure for fishes and improve fishing opportunities, but the role of artificial reefs within the broader estuarine seascape has not been extensively studied. We used a VEMCO Positioning System (VPS) to monitor the fine-scale movements of yellowfin bream (Acanthopagrus australis, referred to as Bream), an estuarine predator and important recreational species. Fish were implanted with acoustic tags with accelerometer sensors (to measure relative fish activity), and their movements monitored on an artificial reef and adjacent habitats. Elevated activity patterns during crepuscular periods indicated that foraging was likely occurring over a large seagrass bed adjacent to the artificial reef system. Alternatively, lower activity was observed when fish were on the artificial reef, which may reflect the role of this habitat as a refuge, or that alternative foraging strategies were being employed. All fish exhibited a high degree of fidelity to the artificial reef on which they were tagged, and there was minimal movement among other reef groups within the array. There was extensive overlap in space use contours for smaller fish on the seagrass edge, but no overlap for larger fish that also tended to forage further afield. These findings have implications for the way in which artificial reefs support fish production, especially the importance of connectivity with other key habitats within the estuarine seascape.     

Fish biomass estimates from the littoral zone of an estuarine coastal lake

The fish community of Swartvlei, a southern African coastal lake, was sampled using gill and lift nets. A primary aim of the research was to determine the fish biomass of the lake shelf region as well as the distribution patterns of marine species which utilize this estuarine system as a nursery and/or foraging area. The catch per unit effort of fishes was more than three times higher in the littoral zone when compared to the pelagic, slope, or profundal zones. Both habitat diversity and available food resources were maximal in the shelf region. The biomass of the littoral fish community during 1980 was estimated at 12.4 g m² wet weight, with detritivorous species contributing 3.2 g m^?2, zoobenthos consumers 2.8 gm², piscivorous species 2.3 g m², herbivorous/epifaunal consumers 2.7 g m^?2, and zooplanktivorous species 1.4 g m². Published information on fish atanding stock estimates from various estuaries and coastal habitats around the world is collated and compared. It is concluded that estuarine fish biomasses do not excced those of productive freshwater or marine environments and that further research is necessary to determine the size and variability of estuarine fish stocks in relation to other ecosystems.     

Stock-Specific Movement and Distribution of Juvenile Chinook Salmon, <Emphasis Type="Italic">Oncorhynchus tshawytscha</Emphasis>, in Sandy Beach Surf Zones of Oregon and Washington,USA

Sandy beach surf zones serve as alternative nursery habitats for juvenile Chinook salmon (0 age) during their early marine residency, a period considered critical due to high and variable mortality rates. Despite the importance of early marine residence, the extent of juvenile salmon surf zone use and movement along sandy beaches is not well understood. Juvenile Chinook salmon distribution and movement were studied in shallow surf zone habitats by sampling from 2006 to 2010 with a beach seine 11 beaches adjacent and distant to four estuary mouths in Oregon and Washington, USA. The estuary of origin of each juvenile was determined using genetic stock identification methods and coded wire tags. Surf zones sampled were within littoral cells, which are stretches of the coastline bordered by rocky headlands, and included estuaries with and without Chinook salmon populations. Juvenile salmonids were only collected at littoral cells with Chinook-inhabited watersheds. Most juveniles (95 %) were present at sandy beaches adjacent (<500 m from estuary mouth) to their estuary of origin. Few Chinook salmon (5 %) were collected at littoral cells that contained non-natal estuaries. These results indicate that juvenile Chinook salmon inhabiting surf zones mostly use beaches adjacent to their estuaries of origin, but some juveniles may reside in beaches distant from their point of ocean entry.     

The importance of physical and biogenic structure to juvenile fishes on the shallow inner continental shelf

Fish-habitat relationships on the shallow inner continental shelf were quantified with video sled and metered beam trawl on Fenwick and Weaver shoals offshore of Maryland and Delaware, U.S. These areas provide megascale physical relief and habitat complexity, but for juvenile fishes, mesoscale and microscale habitat is very important particularly as refuge from predation. At these smaller scales, much of the relief on the inner continental shelf is contributed by bedforms or sand waves and biogenic structures such as tubes, shell beds, or pits. A quantitative association for juvenile fishes between and within benthic habitats was found and related primarily to bedform size and amount of biogenic structure. The incidence of fishes was about four-times higher for large bedforms (> 30 cm wavelength and about 10 cm crest height) relative to smaller bedforms (<30 cm wavelength and about 5 cm crest height). For biogenic structure, going from high patch-mat tube densities to lower densities or no biogenic structure increased fish incidence by 5.4 and 3.3 times, respectively. The significant relationships of fishes with bedform size and density of biogenic structure indicated that seemingly small differences in physical structure of a habitat can make the difference between unacceptable and essential habitat for juvenile fishes. Proximity of complex and simple habitats was important in the diel use of habitat and in balancing pressure of refuge from predation provided by complex habitats with foraging for increased resources available in simpler habitats. During the day, spatially complex habitats comprised ofDiopatra andAsabellides tube mats had about twice as many fishes relative to bare sandy habitats (8.3–9.9 versus 4.0–4.1 fishes 100 m⁻², respectively). At night, the pattern was reversed with more fishes present in the bare sandy habitats (12.4–13.5 versus 5.6–8.7 fishes 100 m⁻²). Some fish, such asAmmodytes spp., were very habitat specific and occurred only on dynamic coarser sands near the top of the shoals. Others, such asUrophycis regia, showed less habitat preference and occurred in all habitats during both day and night. Combining the effects of physical relief and biogenics, the habitat with the highest incidence of fishes had large bedforms with some biogenic structure. More emphasis needs to be placed on quantifying the relationship between fishes and their habitats for the fisheries management concept of essential fish habitat to develop into an effective tool on the inner continental shelf. The juvenile life history stages need to be emphasized because fish-habitat interactions are the strongest for these stages and may be the most ecologically important.     

The distribution of shallow water juvenile fishes in an urban estuary: The effects of manmade structures in the lower Hudson River

The objective of this study was to determine what effect, if any, large pile-supported platforms (piers) have on the habitat distribution and abundance of juvenile fishes. Trapping techniques were used in 1993 and 1994 under piers, in pile fields, and in open-water habitat types in shallow areas (<5 m) in the lower Hudson River estuary (40°44′N, 70°01′W). Nearly 1500 fishes, mostly juveniles, representing 24 species were collected in 1865 trap-days from May through October in the 2-yr study. The presence of relatively large numbers of young-of-the-year (YOY) fish during both years lends support to the idea that shallow areas in the lower Hudson River estuary currently function as nursery habitats for a variety of fishes. Two seasonal assemblages were apparent, but their composition varied somewhat between years.Microgadus tomcod andPseudopleuronectes americanus YOY dominated an early summer assemblage (May–July) while large numbers of YOYMorone saxatilis were collected as part of a late summer assemblage (August–September). The effects of habitat type on fish assemblage structure were significant during both years. Fish abundance and species richness were typically low under piers; YOY fishes were rare andAnguilla rostrata accounted for a large proportion of the total catch. In contrast, YOY fishes dominated collections at pile field and open-water stations, where abundance and species richness were high. These results indicate that habitat quality under the platforms of large piers (>20,000 m²) is probably poor for YOY fishes when compared with nearby pile field and open-water habitat types.     

Tidal Habitats Support Large Numbers of Invasive Blue Catfish in a Chesapeake Bay Subestuary

The introduction of a non-native freshwater fish, blue catfish Ictalurus furcatus, in tributaries of Chesapeake Bay resulted in the establishment of fisheries and in the expansion of the population into brackish habitats. Blue catfish are an invasive species in the Chesapeake Bay region, and efforts are underway to limit their impacts on native communities. Key characteristics of the population (population size, survival rates) are unknown, but such knowledge is useful in understanding the impact of blue catfish in estuarine systems. We estimated population size and survival rates of blue catfish in tidal habitats of the James River subestuary. We tagged 34,252 blue catfish during July–August 2012 and 2013; information from live recaptures (n = 1177) and dead recoveries (n = 279) were used to estimate annual survival rates and population size using Barker’s Model in a Robust Design and allowing for heterogeneity in detection probabilities. The blue catfish population in the 12-km study area was estimated to be 1.6 million fish in 2013 (95% confidence interval [CI] adjusted for overdispersion: 926,307–2,914,208 fish). Annual apparent survival rate estimates were low: 0.16 (95% CI 0.10–0.24) in 2012–2013 and 0.44 (95% CI 0.31–0.58) in 2013–2014 and represent losses from the population through mortality, permanent emigration, or both. The tagged fish included individuals that were large enough to exhibit piscivory and represented size classes that are likely to colonize estuarine habitats. The large population size that we estimated was unexpected for a freshwater fish in tidal habitats and highlights the need to effectively manage such species.     

Community structure of the demersal fish species of Laguna Joyuda,Puerto Rico

A year-long trawl survey of the mangrove-fringed Laguna Joyuda, Puerto Rico yielded 41 species of juvenile and adult fishes. Twelve percent of the species and 55% of the individuals were residents in the lagoon; 56% of the species and 44% of the individuals were cyclic visitors, mostly juveniles of species which spawn offshore. The lagoon yielded fewer species than tropical estuaries in continental regions of the Caribbean and temperate estuaries of North America. However, paralleling other estuarine habitats, Laguna Joyuda supported three primary types of fishes, a resident small flatfish (Achirus lineatus), a complex of transient juveniles (Gerreidae, paralleling the Sciaenidae of higher latitudes), and small planktivores (Anchoa spp.). Seasonal patterns in the abundance of individual species were not strong, but overall abundance showed a wet season maximum, particularly because of recruitment of anchovies and cyclic visitors in April, May, and June. Wet season abundance corresponded with highest water column productivity and detrital input to the benthos. Fishes associated with the water column appeared to show greater variation in abundance than those associated with more stable benthic food webs.     

The fish community of a shallow tropical lagoon in Belize,Central America

Trawl collections indicate that the fish community of the Belize barrier reef lagoon is dominated numerically and in biomass by grunts (Haemulidae), especiallyHaemulon sciurus andHaemulon flavolineatum. Although the gear selected for small sizes, length frequency analysis indicated seasonality in recruitment of the dominant species of grunts. Apogonids and tetraodontiform fishes were also dominant components of the community. Most fishes collected were juveniles of species that occur as adults on the main reef, or were small species that are resident in the lagoon. Of three habitats sampled, the mangrove creek had the greatest relative abundance and biomass of fishes, followed by the seagrass bed and the sand-rubble zone. There were no significant seasonal differences in fish relative abundance or biomass. Community structure analysis indicated a uniqueness in the mangrove fish community. Diversity (H′) was high, and was due to high species richness and evenness of distribution of individuals among species. The Belize barrier reef lagoon serves as an important nursery habitat for juvenile fishes.     

Patterns in use of estuarine habitat by juvenile English sole (Pleuronectes vetulus) in four Eastern North Pacific estuaries

English sole (Pleuronectes vetulus) is one of a few commercially important marine fishes on the Pacific coast of North America that use estuarine areas as nurseries for juvenile stages. Trawl surveys of four United States Pacific Northwest estuaries were conducted to determine spatial patterns of juvenile English sole residence in estuaries during 1998–2000. Additional data from 1983–1988 were also analyzed. Two size classes of juvenile English sole were identified during surveys, with densities of small (Total length [TL] <50 mm) sole ranging from 0 to 11,300 fish ha^?1 across all sites, and densities of large (TL 50–150 mm) sole ranging from 0 to 33,000 fish ha^?1 across all sites. Principal components analysis of static habitat data collected at each trawl survey site was used to define habitat types within each estuary, and discriminant function analysis was used to test the resulting classification scheme. Both small and large cohort English sole used lower side channel locations at significantly higher densities than other estuarine areas. Small English sole also showed significant relationships with both bottom temperature and depth. These patterns in habitat use were consistent across all estuaries and indicate that English sole used shallow depth areas surrounded by extensive tidal flats, where temperatures were optimal for growth. The analysis also suggested a carrying capacity may exist for large English sole in nursery estuaries.     

Composition and distribution of larval fishes in New Jersey high marshes

The surface of the salt marsh is an important, but largely unrecognized, site for fish reproduction and larval growth. In an attempt to determine the composition and distribution of fishes utilizing these habitats, we sampled larval and juvenile fish with plankton nets, dip nets, and traps at a variety of microhabitats (tidal and nontidal ponds and ditches and the marsh surface) in three New Jersey high marshes. Two of the three marshes had been altered for mosquito control. During April to September 1980, we collected over 2,400 larvae and juveniles. All study sites were dominated by the larvae of the resident killifishes (Fundulus heteroclitus, Cyprinodon variegatus, F. luciae, andLucania parva) and less commonlyMenidia beryllina. However, the occurrence and abundance of each species varied with microhabitat. Larval production in all three marshes peaked during June–July, but extended from May until September. In most instances juveniles of the dominant fishes had microhabitat preferences similar to the larvae. High marshes may be more important for fish production than previously recognized because they serve as nursery areas for the resident killifishes.     

Regional Correspondence in Habitat Occupancy by Gray Snapper (Lutjanus griseus) in Estuaries of the Southeastern United States

Reef fishes, such as gray snapper, support important recreational and commercial fisheries and use a variety of habitats throughout ontogeny. Gray snapper juveniles may be found in estuarine nursery areas, such as seagrass beds, or mangrove shorelines, while adults are most often found in deep channels and farther offshore, associated with hard-bottom habitats. Juvenile and subadult gray snapper were collected from 1996 through 2009 during long-term fishery-independent monitoring of several estuarine systems along the Gulf and Atlantic coasts of Florida. Indices of abundance and habitat suitability were constructed for gray snapper to determine size-specific relationships between abundance, habitat, and environmental conditions. Juvenile and subadult gray snapper were collected year-round only in the southernmost estuaries but were most common from July through December in all estuaries sampled. In addition to timing of estuarine occupancy, abundance varied with latitude; gray snapper were more frequently collected in warmer, southern estuaries. In general, gray snapper were most abundant in euhaline areas with a high percentage of submerged aquatic vegetation (SAV) and, in most cases, where overhanging shoreline vegetation was also present. Annual abundance varied over the sampling period, with some juvenile peaks in abundance translating to subadult peaks in subsequent years. Although strong correspondence between juvenile and subadult populations was not observed in all systems, long-term, broad-scale habitat selection patterns as described in this study are critical to more effectively assess populations of estuarine-dependent species.     

Movements of spawning rainbow smelt,Osmerus mordax,in a massachusetts estuary

Movements of spawning rainbow smelt, Osmerus mordax, were followed in the Parker River estuary, Massachusetts during 1974 and 1975. Fish marked with vinyl subcutaneous tags (n=1,492) or fin clips (n=577) were recaptured on three separate spawning sites in three different tributaries; the distribution patterns of marked fish indicated a homogeneous spawning stock. Interstream movement may have been facilitated by tidal transport since smelt ascended to the spawning sites on flood tides and moved downstream as tides ebbed. Rates of recapture of fish tagged on the spawning areas were 2.61 and 5.61 times greater for males than females in 1974 and 1975 respectively. Individual tagged males were recovered up to four times during the spawning period; females were recaptured a maximum of once. The proportion of age II and older females sampled from the angling fishery prior to spawning in 1975 (47.38%) was greater than the cumulative proportion sampled on the spawning sites (11.93%) due to longer spawning period of individual males.     

Distribution and community structure of ichthyoplankton in Laguna Madre Seagrass meadows: Potential impact of seagrass species change

Seasonal ichthyoplankton surveys were made in the lower Laguna Madre, Texas, to compare the relative utilization of various nursery habitats (shoal grass,Halodule wrightii; manatee grass,Syringodium filiforme; and unvegetated sand bottom) for both estuarine and offshore-spawned larvae. The species composition and abundance of fish larvae were determined for each habitat type at six locations in the bay. Pushnet ichthyoplankton sampling resulted in 296 total collections, yielding 107,463 fishes representing 55 species in 24 families. A broad spectrum of both the biotic and physical habitat parameters were examined to link the dispersion and distribution of both pre-settlement and postsettlement larvae to the utilization of shallow seagrass habitats. Sample sites were grouped by cluster analysis (Ward’s minimum variance method) according to the similarity of their fish assemblages and subsequently examined with a multiple discriminant function analysis to identify important environmental variables. Abiotic environmental factors were most influential in defining groups for samples dominated by early larvae, whereas measures of seagrass complexity defined groups dominated by older larvae and juveniles. Juvenile-stage individuals showed clear habitat preference, with the more shallowHalodule wrightii being the habitat of choice, whereas early larvae of most species were widely distributed over all habitats. As a result of the recent shift of dominance fromHalodule wrightii toSyringodium filiforme, overall reductions in the quality of nursery habitat for fishes in the lower Laguna Madre are projected.     

Hydroacoustics as a tool for assessing fish biomass and size distribution associated with discrete shallow water estuarine habitats in Louisiana

We developed a relative index of fish biomass and size distribution in ultra-shallow waters (< 2 m) of Barataria Bay, Louisiana, based on the comparison of horizontal hydroacoustic data with gill net and push trawl catches in an effort to understand the role that habitat plays in both fish biomass and distribution. Exclosure net experiments indicated that the contribution of acoustic backscattering from sources other than fishes were negligible. Split-beam transducer, gill net, and push trawl sampling were conducted concurrently in Barataria Bay to provide information on fish composition and length distributions and for comparisons among gear types. Results suggest that acoustic fish biomass was generally higher in the low salinity stations and lower at the high salinity stations, at least in March 2004. We observed a greater mean length of fishes associated with oyster shell habitats when compared to adjacent sand-mud habitats. This paper demonstrates the utility of hydroacoustics as a tool to quantify relative acoustic fish biomass and size distribution associated with common estuarine habitats in ultra-shallow waters. This study also illustrates the potential of using acoustics for augmenting traditional sampling procedures.     

Comparison of habitat use by estuarine fish assemblages in the Acadian and Virginian zoogeographic provinces

Comparison of the relative abundance of fish species from different life-history groups and their temporal patterns of estuarine habitat use from two estuaries north and south of Cape Cod indicates that the Cape acts as a zoogeographic boundary. Between April 1988 and December 1989, monthly seine and trawl samples were collected from nearshore, shallow-water marsh, and beach and deeper open-water habitats in Wells Harbor, Maine, and Waquoit Bay, Massachusetts. Forty-eight species and 80,341 individuals were collected from Waquoit Bay compared to 24 species and 22,561 individuals from Wells Harbor. Waquoit Bay had proportionally fewer resident species and more marine, nursery, and occasional species than Wells Harbor. Annual density and biomass values were greater across all habitats in Waquoit Bay, with the summer values from the marsh habitat an order of magnitude higher than comparable summer data from the Wells habitats. We suggest that marsh and beach habitats provide a nursery area for young-of-the-year fishes, while deeper, open-water habitats serve as a corridor for fishes moving to nearshore habitats or serve as a refuge during low tide.     

Development and validation of an estuarine biotic integrity index

We tested hypotheses about how estuarine fish assemblages respond to habitat degradation and then integrated these responses into an overall index, the Estuarine Biotic Integrity Index (EBI), which summarized observed changes. Fish assemblages (based on trawl catches) and habitat quality were measured monthly or biweekly at nine sites in two estuaries from March 1988 to June 1990. Submerged aquatic vegetation habitats were classified as low or medium quality based on year-round measurements of chemical and physical characteristics (phytoplankton blooms; macroalgae; dissolved oxygen; nutrients; dredged channels). We tested 15 metrics and selected 8 for inclusion in the EBI: total number of species, dominance, fish abundance (number or biomass), number of nursery species, number of estuarine spawning species, number of resident species, proportion of benthic-associated fishes, and proportion abnormal or diseased. Fish assemblages in low-quality sites had lower number of species, density, biomass, and dominance compared with medium-quality sites. Fish abundance peaked in July and August, and was lowest in January to March. The seasonal cycle in low-quality sites was damped compared with medium-quality sites. Abundances of fishes using estuaries as a spawning and nursery area and of benthic species were lower in low-quality sites compared to medium-quality sites. The individual metrics and the overall index correlated with habitat degradation. The EBI based on biomass did not do better than the EBI based on number, indicating that the extra effort to obtain biomass may not be warranted. We suggest the EBI is a useful indicator of estuarine ecosystem status because it reflects the relationship between anthropogenic alterations in estuarine ecosystems and the status of higher trophic levels.     

Do Juvenile White Perch Morone americana Grow Better in Freshwater Habitats of the Blackwater River Drainage (Chesapeake Bay, MD, USA)?

Increasing rates of freshwater habitat loss in the Chesapeake Bay (and elsewhere) have renewed interest in the role of freshwater in population integrity for euryhaline fishes. Freshwater habitats may be important nurseries for juveniles of anadromous species. Using length?Cweight residuals and scales, we determined if body condition and growth of juvenile (<120?mm total length) white perch Morone americana (a semi-anadromous species) differed between brackish and freshwater tributaries within the Blackwater River drainage (Chesapeake Bay Watershed, U.S.A.). We then examined how monthly variation in body condition varied with monthly variation in selected environmental factors. Body condition differed between tributaries and was greater in freshwater (specific conductivity <0.45?mS) than brackish water when water temperature was greater than 9.6°C. White perch growth rates did not differ between tributaries, except for a short time during summer or early fall. Some anadromous fishes may spawn in freshwater to promote greater body condition, thereby ensuring a quality contingent of individuals for the population. With continued loss or impairment of freshwater habitat, the availability of nurseries for juvenile white perch will be reduced and reduce the number of quality juveniles recruiting to the adult population.     

Recruitment and Habitat Use of Early Life Stage Tarpon (<Emphasis Type="Italic">Megalops atlanticus</Emphasis>) in South Carolina Estuaries

Our study was designed to examine early life stage tarpon (Megalops atlanticus) recruitment, habitat use, and residency in coastal environments near the northern limit of their distribution in the western Atlantic Ocean. We employed a multi-faceted approach to (1) collect ingressing larval tarpon on nighttime flood tides at multiple sites, (2) document larval and juvenile tarpon use of natural high marsh pools, and (3) examine juvenile tarpon movement and behavior in managed marsh impoundments, all in the North Inlet-Winyah Bay estuarine system of South Carolina, USA. The timing of recruitment (June through November) and size of larvae (mean ± standard deviation = 23 ± 3 mm standard length [SL]) during estuarine ingress was similar to that reported from other subtropical locations in the region. Soon after recruiting into the system, larval and small juvenile tarpon (47 ± 25 mm SL) co-occurred in high marsh pools from July to November, and large juveniles (201 ± 34 mm SL) were also present in marsh impoundments during this same time period. An increase in tarpon length over time during their residency in high marsh pools and the relatively large size they attain in marsh impoundments indicate these environments may function as favorable nursery habitats. As water temperatures decreased during October and November, juvenile tarpon emigrated from these estuarine habitats. Tarpon appear to use a variety of estuarine habitats in coastal South Carolina from summer through late fall during their early life stage development. The fate of these individuals after they leave estuarine habitats at the onset of winter in this region is currently unknown.     

What Makes Nearshore Habitats Nurseries for Nekton? An Emerging View of the Nursery Role Hypothesis

Estuaries and other coastal habitats are considered essential for the survival of early life stages of commercial, recreational, and other ecologically important species. While early designations simply referred to habitats with higher densities of juveniles as nurseries, the definition was improved by arguing that contribution per unit area to the production of individuals that recruit to adult populations is greater, on average, in nursery habitats. However, this and related approaches typically consider critical habitats as individual, homogeneous entities that are static in nature and do not specifically incorporate important dynamics that determine nursery function. The latter include environmental variability, estuarine hydrodynamics, trophic coupling, ontogenetic habitat shifts, and spatially explicit usage of habitat patches and corridors within larger seascapes. Subsequent studies have identified important factors that regulate nursery value, and researchers working independently across the globe have not only supported the advances made in defining the processes underlying nursery function but, as set forth in this narrative, have advanced it while suggesting that much work still needs to be done to improve our understanding of the links between juvenile nekton survival and the estuarine-coastal seascape. We discuss the current nursery role hypothesis and the data supporting (or refuting) it along with the implications for management of estuarine habitats for the conservation or restoration of nursery function.     

Estuarine production of juvenile dungeness crab (cancer magister) and contribution to the Oregon-Washington coastal fishery

Estuaries provide nursery habitat for juvenile stages of several commercial decapod crustaceans worldwide, and those in the Northeastern Pacific are viewed as providing this function for Dungeness crab,Cancer magister. It is difficult to ascertain the degree to which such estuarine production of juveniles eventually contributes to coastal adult populations and fisheries since there are no direct surveys of adult abundance. As other authors have done, we used fishery landings data to compute the long-term average contribution of 1 + juvenile crab populations reared in estuaries to future coastal fisheries. We focused on Oregon and Washington states, but grouped landings in two large geographic zones by combining fishery ports as adjacent to Large Estuarine Zones (LEZ; Grays Harbor and Willapa Bay, Washington, and both sides of the Columbia River) and Small Estuarine Zones (SEZ; all other ports in Oregon). Mortality estimates were used to reduce 1 + crab abundance to surviving legal males, and portrayed as percent of the fisheries. Trends in the SEZ indicate that an average of only about 5–7% of estuarine production adds to the coastal adult population and contributes about $0.7 million to the fishery. The contribution is 25–30% in the LEZ (but may be higher since interannual density varies up to 5 times) and is worth about $3.9 million based on present ex-vessel value. Analyses of crab distribution and density indicate that the majority of an estuarine population (50–80%) is located in lower side channels (LSC) in spring and summer where temperature is higher and prey within and on adjacent intertidal flats is high. The potential average dollar value of equivalent legal male crab produced from the juvenile population is about $180 ha^?1 in LSC (but $280 ha^?1 in Grays Harbor where long-term density is highest), and lower in other estuarine habitats ($50–100 ha^?1). Estuarine juvenile production provides a relatively stable source of recruits to coastal adult populations, and large systems in the LEZ are important nurseries. Since direct coastal settlement of larvae does occur but is highly variable, the estuarine contribution may be especially important when physical forcing or unusual events lead to low survival of the coastal 0+ cohort. An unusually long period of very low landings in the LEZ from 1981–1987 is interpreted in light of the Mount St. Helens eruption (1980) and subsequent transport and deposition of very fine silt fractions over much of the LEZ nearshore shelf that may have adversely affected several year classes of small, early benthic phase juveniles at that time.