Portsmouth Harbor Research Articles

Active management is required to turn the tide for depleted Ostrea edulis stocks from the effects of overfishing, disease and invasive species.

The decline of the European oyster Ostrea edulis across its biogeographic range has been driven largely by over-fishing and anthropogenic habitat destruction, often to the point of functional extinction. However, other negatively interacting factors attributing to this catastrophic decline include disease, invasive species and pollution. In addition, a relatively complex life history characterized by sporadic spawning renders O. edulis biologically vulnerable to overexploitation. As a viviparous species, successful reproduction in O. edulis populations is density dependent to a greater degree than broadcast spawning oviparous species such as the Pacific oyster Crassostrea (Magallana) gigas. Here, we report on the benthic assemblage of O. edulis and the invasive gastropod Crepidula fornicata across three actively managed South coast harbors in one of the few remaining O. edulis fisheries in the UK. Long-term data reveals that numbers of O. edulis sampled within Chichester Harbour have decreased by 96%, in contrast numbers of C. fornicata sampled have increased by 441% over a 19-year period. The recent survey data also recorded extremely low densities of O. edulis, and extremely high densities of C. fornicata, within Portsmouth and Langstone Harbours. The native oyster’s failure to recover, despite fishery closures, suggests competitive exclusion by C. fornicata is preventing recovery of O. edulis, which is thought to be due to a lack of habitat heterogeneity or suitable settlement substrate. Large scale population data reveals that mean O. edulis shell length and width has decreased significantly across all years and site groups from 2015 to 2017, with a narrowing demographic structure. An absence of juveniles and lack of multiple cohorts in the remaining population suggests that the limited fishing effort exceeds biological output and recruitment is poor. In the Langstone & Chichester 2017 sample 98% of the population is assigned to a single cohort (modal mean 71.20 ± 8.78 mm, maximum length). There is evidence of small scale (<5 km) geographic population structure between connected harbors; the 2015 Portsmouth and Chichester fishery populations exhibited disparity in the most frequent size class with 36% within 81–90 mm and 33.86% within 61–70 mm, respectively, the data also indicates a narrowing demographic over a short period of time. The prevalence of the disease Bonamiosis was monitored and supports this microgeographic population structure. Infection rates of O. edulis by Bonamia ostreae was 0% in Portsmouth Harbor (n = 48), 4.1% in Langstone (n = 145) and 21.3% in Chichester (n = 48) populations. These data collectively indicate that O. edulis is on the brink of an ecological collapse within the Solent harbors. Without effective intervention to mitigate the benthic dominance by C. fornicata in the form of biologically relevant fishery policy and the management of suitable recruitment substrate these native oyster populations could be lost.

High-frequency seafloor scattering in a dynamic harbor environment: Observations of change over time scales of seconds to seasons

Predicting sonar performance in a harbor environment can be made challenging by the dynamics of the upper and lower surface boundaries. In this talk we examine measurements of the seabed in Portsmouth Harbor, NH. Tidally influenced currents in the Piscataqua River make Portsmouth Harbor one of the most challenging commercial ports to navigate in the northeastern United States. The level of interaction between these currents and the harbor floor is a function of the substrate type. Stereo-camera observations in a sand-wave field near the harbor entrance show fluctuations in microscale roughness and optical reflectance at time scales of seconds during periods of high current. Despite the observed microscale dynamics in the sand-wave field, acoustic observations of both high-frequency seabed scattering strength and mesoscale topography in the same area appear stationary over time scales up to seasons. The low-level of observed fluctuations in scattering strength from the sand-wave field are commensurate with...

The role of uniqueness in destination branding: the case of historical Portsmouth harbor

Purpose – The purpose of this paper is to examine the potential for utilizing a unique resource, such as the Historic Portsmouth Harbor, in order to differentiate the local brand. Design/methodology/approach – The objective of the paper is to examine the role of unique local resources and attractions as a source of competitive advantage through destination branding. Findings – The main findings of the paper indicate that policy makers and destination managers should more proactively utilize the unique elements of the Historic Portsmouth Harbor “brand,” as opposed to the commonplace “waterfront city” brand. This could be achieved by staging events of international significance or through a bid for gaining world heritage status. In addition to that, the paper argues that in order for this branding initiative to have a higher impact, a prominent high profile individual should be appointed. This individual could act as a leader or “brand ambassador” in order to attract stakeholder interest and participation. Originality/value – The paper could be of value to destination managers and marketing organizations in a local, sub-regional and regional level.

High‐frequency one‐way propagation experiments in Portsmouth Harbor, NH.

Portsmouth Harbor is a shallow water estuary with 3‐m tide heights and 2‐m/s tidal currents, exhibiting strong mixing between ocean water and several fresh water inputs. In order to help characterize the limitations for underwater acoustic positioning systems in this environment, high‐frequency (40 kHz) one‐way acoustic propagation measurements were made at ranges up to 1 km in an area where the maximum depth reached 25 m. Synchronized acoustic transmissions were made from a bottom mounted projector as well as from a near‐surface projector mounted on a moving research vessel. The signals were received at a pier‐mounted hydrophone. Measurements of signal levels and arrival times show strong signatures from a variety of phenomenon including changes in tide height, changes in sound speed gradients in response to the tidal forcing functions, and turbulent mixing in the water. Each of these will be discussed in relation to signal fluctuations and constraints on measuring pulse arrival times.

ENVIRONMENTAL RESPONSE MANAGEMENT APPLICATION

ABSTRACT The Coastal Response Research Center (CRRC), a partnership between the University of New Hampshire (UNH) and NOAA'S Office of Response and Restoration (ORR), is leading an effort to develop a data platform capable of intefacing both static and real-time data sets accessible simultaneously to a command post and assets in the field with an open source internet mapping server. The Environmental Response Management Application (ERMA™) is designed to give responders and decision makers ready access to geographically specific data useful during spill planning/drills, incident response, damage assessment and site restoration. In addition to oil spill and chemical release response, this website can be relevant to other environmental incidents and natural disasters, responses and regional planning efforts. The platform is easy to operate, without the assistance of Information Technology or Geographic Information Systems (GIS) specialists. It allows users to access individual data layer values, overlay relevant data sets, and zoom into segments of interest. The platform prototype is being developed specifically for Portsmouth Harbor and the Great Bay Estuary, NH. The prototype demonstrates the capabilities of an integrated data management platform and serves as the pilot for web-based GIS platforms in other regions.

Heart rate reflects osmostic stress levels in two introduced colonial ascidians Botryllus schlosseri and Botrylloides violaceus

The influence of abiotic factors on the establishment and success of invasive species is often difficult to determine for most marine ecosystems. However, examining this relationship is critical for predicting the spread of invasive species and predicting which habitats will be most vulnerable to invasion. Here we examine the mortality and physiological sensitivity to salinity of adult colonies of the colonial ascidians Botryllus schlosseri and Botrylloides violaceus. Adult colonies of each species were exposed to abrupt changes in salinity (5, 10, 15, 20, 25, 30 psu) in the laboratory. Salinity ranges used in the laboratory corresponded with those of the field distributions of B. violaceus and B. schlosseri in the Great Bay Estuary, NH. Heart rate was used as a proxy for health to assess the condition of individual colonies. Heart rates were monitored daily for approximately 2 weeks. Results revealed that both species experienced 100% mortality after 1 day at 5 psu and that their heart rates declined with decreasing salinity. Heart rates of B. schlosseri remained consistent between 15 and 30 psu and slowed at 10 psu. Heart rates of B. violaceus remained constant between 20 and 30 psu, but slowed at 15 psu. These laboratory results corresponded to the distribution of these species in estuaries, indicating salinity is a key factor in the distribution and dominance of B. schlosseri and B. violaceus among coastal and estuarine sites. Furthermore, physiological differences to salinity were found between colonies of B. schlosseri in the Venetian Lagoon and colonies in Portsmouth Harbor, suggesting adaptation to environmental variables.

Effect of grazing by Canada geese Branta canadensis on an intertidal eelgrass Zostera marina meadow

Fishing Island, in Portsmouth Harbor on the Maine-New Hampshire border (USA), is the site of an intertidal eelgrass (Zostera marina L.) bed that is part of SeagrassNet, an international program for long-term seagrass monitoring. Eelgrass bed parameters of canopy height, percent cover, and aboveground biomass have been monitored quarterly since October 2001 using the Sea- grassNet protocol. A flock of nearly 100 Canada geese Branta canadensis L. over-wintered at Fishing Island and grazed on eelgrass from January to April 2003, an event that had not been seen at this meadow in 2 decades of observation. Before Canada geese were present, eelgrass parameters demonstrated seasonal fluctuations typical of the region. During the grazing event, eelgrass parame- ters declined drastically, and biomass losses reached 680 g m -2 in parts of the meadow. SeagrassNet data demonstrated that eelgrass did not recover after the geese departed. Additional fieldwork con- ducted from February to July 2003 showed that eelgrass recruitment via sexual reproduction at Fish- ing Island was minimal, and vegetative recovery was impeded by Canada goose consumption of the plant meristems. Unlike studies in other locations, which show seagrass quickly rebounding from annual grazing events, eelgrass at Fishing Island showed little recovery from Canada goose grazing through July 2003.

The role of colonial ascidians in altering biodiversity in marine fouling communities

A suite of invasive species, each with their own unique morphologies, have recently becomemembers of Gulf of Maine, ME USA subtidal communities (Harris and Tyrrell, 2001; Pederson et al., 2005). Three of these species, Botrylloides violaceus, Diplosoma listerianum and Didemnum sp., are colonial ascidians and have become major space occupants in New England fouling communities (Berman et al., 1992; Osman and Whitlatch, 1995, 1999; Whitlatch et al., 1995; Bullard et al., 2007-this issue). They are warm water, two-dimensional species that dominate during seasons of greatest fouling species recruitment (Stachowicz et al., 2002). Therefore, the presence of these species in the Gulf of Maine may significantly influence the recruitment of other species to fouling communities. The goal of this study was to examine the role of the three colonial ascidians in the development of fouling communities by comparing the recruitment of species onto panels containing organisms with different functional morphologies. We conducted field studies at two sites with similar species composition in Portsmouth Harbor, Newcastle, New Hampshire, USA. The communities occupying the floating docks at these sites included blue mussels (Mytilus edulis), the sea anemone Mitridium senile, encrusting

Sheath length as a monitoring tool for calculating leaf growth in eelgrass ( Zostera marina L.)

Recent advances have improved ease and accuracy in seagrass growth measurements. Despite these improvements, seagrass leaf growth can be difficult to measure effectively; current methods are destructive to the plants and require at least two site visits per growth period. We used the “previous growth” of Ibarra-Obando and Boudouresque [Ibarra-Obando, S.E., Boudouresque, C.F., 1994. An improvement of the Zieman leaf marking technique for Zostera marina growth and production assessment. Aquat. Bot. 47, 293–302.] to develop a relationship between sheath length and leaf growth in eelgrass, Zostera marina L., and we demonstrated that a simple, non-destructive method allows reliable calculation of eelgrass leaf growth (mg shoot −1 day −1) based on sheath length. We measured eelgrass sheath length and leaf growth for 18 months, from November 1999 to April 2001, at a site in Portsmouth Harbor on the border of New Hampshire and Maine, USA. Regression analyses showed a high coefficient of determination between sheath length and leaf growth, demonstrating that sheath length reliably reflected eelgrass leaf growth. We also showed that four seasonal measurements were sufficient to establish a significant relationship between sheath length and leaf growth. After a regression of sheath length and leaf growth has been established for a site, eelgrass sheath length can be measured in situ to accurately calculate leaf growth, eliminating both the need for destructive growth measurements and the need to mark and relocate plants.

Coming into the Light: The Rediscovery and Reuse of Naval Heritage Buildings

The magnificent heritage of natives built by the finest architects, expressive of national pride, has not in some countries been perceived as part of the cannon of historic buildings, while in others naval buildings are cherished as key settings of national history. This paper examines why these differences occur, and how they influence the revaluing of naval heritage, once its maritime existence is over. What makes historic defense sites a special case in brown land redevelopment is their diversity of architecture and engineering. “The beauty of utility” which historic military and naval buildings exemplify is at once expressive of state power and taste, and a particular challenge to appropriate reuse in physical and economic terms. Building conservation law and practice may inhibit or enable the development of new activities within them. In the best examples of beneficial reuse, naval buildings’ inherent robustness is respected and even celebrated, not obliterating their long history, but adding new layers of meaning and association. Illustrations of the paper’s themes will include the recent conversion of the Royal Hospital at Greenwich for universities, new uses for naval buildings around Portsmouth Harbor, the Arsenal buildings in Venice, Swedish naval buildings in Karlskrona and the Royal Woolwich Arsenal on the River Thames in London.

Calibrated seafloor acoustic backscatter imagery with a 160-kHz multibeam sonar

A fully calibrated multibeam swath sonar operating at 160 kHz was used to collect seafloor acoustic backscatter data in Portsmouth Harbor, NH. Acoustic backscatter levels integrated over each beam’s footprint are compared with levels integrated over the sonar pulse’s footprint commonly used in sidelooking sonar imagery of the seafloor. In both cases, concurrent swath bathymetry is used to convert arrival angles measured at the sonar into angles of incidence relative to the seafloor. These results are contrasted against an extensive sedimentary and acoustic database obtained in 2001 with high frequency seafloor mapping sonars O(100–500 kHz) while assembling a common data set for the 2nd International Conference on High-resolution Surveys in Shallow Water 2001 (http://www.ccom.unh.edu/shallow/shallowsurvey.htm).

In situ measurement of sediment acoustic properties and relationship to multibeam backscatter

In support of the Office of Naval Research’s Geoclutter Program, in situ acoustic and resistivity measurements were obtained using ISSAP, a device developed and built by the Center for Coastal and Ocean Mapping. The primary focus of this research is to understand the relationship between remotely measured backscatter and the acoustic properties of surficial sediments. The field area selected was Portsmouth Harbor (NH) due to the comprehensive sonar data set collected during the Shallow Water Survey 2001 conference. Seawater and surficial sediment measurements of compressional wave sound speed, attenuation, and resistivity were obtained at a large number of stations selected to represent a range of seafloor backscatter types. The ISSAP platform was configured with two orthogonal matched pairs of transducer probes operating at frequencies of 47 and 65 kHz. A Van Veen grab sampler was also used to obtain a sediment sample at each station. Subsampling tubes were used to obtain undisturbed samples; laboratory measurements of density, compressional wave speed and attenuation, resistivity, and grain size were completed. For a small subset of samples, selected to represent a range of sediment types, measurements of permeability, shear wave speed, and attenuation were completed. [Research supported by ONR Grant No. N00014-00-1-0821.]

Processing Data for Seafloor Mapping: Integration and Metrics

Today's state-of-the-art hydrographic survey instrumentation produces higher resolution and more densely sampled measurements than were available in the past. This supports improvements in the definition of seafloor features and characteristics, however, it also places more stringent requirements on the systems used to process seafloor survey data. In shallow water environments bathymetric sampling rates can exceed 4000 soundings per second and data from Digital Side-Scan Sonar Systems can exceed 1 Gb/hr. In support of the Second International Conference on High-Resolution Surveys in Shallow Water, and working in cooperation with Reson Inc., Goleta, Ca., and the University of New Hampshire's Center for Coastal and Ocean Mapping (CCOM), Science Applications International Corporation (SAIC), Newport, RI conducted a survey of the conference common data set test area in Portsmouth Harbor using a Reson 8125 dual-head sonar system. The acquired data were made available as part of the conference common dataset. An area-based approach to data cleaning, including the use of an automated filter for spike detection, is presented. Resource and effort metrics associated with the processing of samples from the common data set are provided. This includes corrector application, data cleaning, validation, and quality control. Results from the area-based approach are compared with results from a traditional line-oriented approach. Three bathymetric datasets from Portsmouth Harbor are compared and the results reported.

Isotope ratios of 206Pb/ 207Pb in eelgrass, Zostera marina, indicate sources of Pb in an estuary

We deployed hydroponic eelgrass, Zostera marina L., to test its use as a sentinel accumulator and indicator of the source of water-borne lead (Pb) contamination in the marine environment. Eelgrass was deployed unrooted in the water column in the vicinity of the Portsmouth Naval Shipyard, located on Seavey Island in Portsmouth Harbor of New Hampshire and Maine, offshore from seepage sites near the Jamaica Island landfill (JIL). Deployed eelgrass, water samples from seepage sites, and sediment from the deployment sites were analyzed for Pb concentration and stable Pb isotopic composition. Isotopic composition was used to distinguish recent anthropogenic Pb inputs from background Pb in the estuary. Isotope ratios indicated that two groundwater seeps were a source of recent anthropogenic Pb (i.e. industrial Pb from the landfill) to Jamaica Cove. The eelgrass that showed the strongest presence of industrial Pb (having the lowest 206Pb/ 207Pb) was closest to a high volume seep that drained from the JIL and had a similar isotope signature as well as elevated Pb concentrations. These data confirm a source of water-borne industrial Pb in the estuary and show that eelgrass can function as a sentinel accumulator of Pb from anthropogenic sources.

Marine Fish Haematozoa from New Brunswick and New England

Of 1142 fish (68 species) examined, 140 (21 species) yielded blood parasites. Overall incidence was much higher at St. Andrews, N.B., than at Woods Hole, Mass., as was the variety of fish harbouring haematozoa — 15 species (46.9%) in the former case, but only 4 (9.3%) in the latter.Trypanosoma rajae Laveran and Mesnil and Cryptobia bullocki Strout are new records for Canada, Haemogregarina delagei Laveran and Mesnil has not previously been reported from the western side of the Atlantic, and the present finding of an undesignated species of Haemohormidium Henry (a babesioid genus with which Babesiosoma Jakowska and Nigrelli is now synonymized) is the first from North American marine fish. New hosts and localities are listed for Haemogregarina bigemina Laveran and Mesnil, H. platessae Lebailly, H. aeglefini Henry, H. myoxocephali Fantham et al., and certain unidentified haemogregarines. Haemogregarina urophysis Fantham et al. is relegated to synonymy with H. aeglefini; and H. gadi pollachii Henry and H. pollachii Henry are discarded as nomina nuda. Myxosporidians of the genus Kudoa are reported (presumably as contaminants derived from slit muscle) in blood films from six hosts.Haemogregarina mavori n.sp., from Passamaquoddy Bay Macrozoarces americanus, averages 6.4 × 2.9 μ. Broadly oval to reniform and with a large, subterminal nucleus, it is found in erythrocytes that are shorter and broader than normal and exhibit marked nuclear displacement.Piscine erythrocytic necrosis (PEN) is a degenerative infection responsible for massive red blood cell destruction in Gadus morhua (Passamaquoddy Bay) and also found in Liparis atlanticus (Kent Island, N.B.) and Myoxocephalus octodecemspinosus (Portsmouth Harbor, N.H.). A distinctive inclusion body formed in the cytoplasm of infected red cells recalls similar bodies associated with Pirhemocyton Chatton and Blanc and Toddia França. Erythrocyte nuclei disintegrate with the liberation of viruslike particles formed in vesicles within them.