Coastal Maine Research Articles

New Insights about Upwelling Trends off the Portuguese Coast: An ERA5 Dataset Analysis

In recent decades, several studies have highlighted the importance of the temporal and spatial structure of upwelling in defining the high levels of productivity of coastal upwelling systems. This work intends to assess the temporal and spatial trends of upwelling along the west and south Portuguese coasts from 1979 to 2020, comparing the patterns between these regions. Two different methodologies to calculate the upwelling indexes (UI), based on wind and sea surface temperature (SST) data, were applied to relate the wind-induced upwelling-favourable conditions (UIET) with the expected response on superficial waters, as indicated by the SST patterns (UISST). The upwelling-favourable conditions are quite consistent and more frequent and intense on the west coast than on the south coast. Spatially, it was verified from the UIET that upwelling-favourable conditions are more intense in association with the main west coast capes and that there is an intensification of favourable winds towards Cape São Vicente, both on the west and south coasts. Seasonally, upwelling-favourable UIET was found to be more consistent in the summer on both coasts. However, it also exists in the winter months. In terms of interannual variations, it should be highlighted that between 1992 and 2005 more intense favourable conditions and an apparent change in the seasonality after 2015 were found. Although some of the results derived from the UIET are corroborated by the UISST (namely, the main spatial trends and interannual variations in the upwelling intensity), several uncertainties are associated with the last index that interfere with its interpretation. For future works, it is advisable to develop a more robust SST-based index that can circumvent the uncertainties pointed out in the present study.

Large café-au-lait spots on a 5-year-old boy

Large café-au-lait spots on a 5-year-old boy

Origin and Forming of Hacham Island in Khor Al-Zubair Channel, Southern Iraq

The marine geophysical survey was conducted using Sub Bottom Profiler and Side Scan Sonar techniques, integrated by petrographic analyses including grain size distribution, mineralogical and fauna analyses of the Hacham island and surrounding area. The island is located in the south part of the Khor Al Zubair channel southwest of the Basrah, Southern Iraq. The study aims to determine the origin and stages of the island formation. This study concluded that there is more than one factor that contributes forming this island represented by tectonic, morphological and sedimentological factors. The results of marine geophysical surveys revealed that the island and its surroundings were affected by the neotectonic activity that exposed the lower part of the Mesopotamian Basin, which in turn caused the lower part of the Khor Al-Zubair channel to meander eastward because of its impact by the fault that separated Warbah island from the Iraqi coast, forming Khor Shaitanah. The meandering of the Khor Al-Zubair course was accompanied by a decrease in flow velocity and thus a decrease in the channel’s ability to carry more sediments, therefore the Khor has to take another course, this waterway separated the island from the main east Iraqi coast. The results of the grain size distribution, mineral identification and fauna analyses indicated a variety of sediment supplying sources of the island, represented by the floods deposits of rivers and side drifts of the surrounding area, in addition to the aeolian deposits transported from the west and northwest Dibdibba Formation. The present study also concluded that the central East shore part of the island is exposed to erosion as a result of a submerged wreck in the waterway that separates the island from the coast.

Benefits and Challenges of a Stakeholder-Driven Shellfish Toxicity Forecast in Coastal Maine

Paralytic shellfish poison (PSP) is a human health concern for shellfish aquaculture and wild harvest. This paper discusses lessons learned from a forecasting program for PSP in coastal Maine, USA, designed based on stakeholder input, and run in an operational mode for the 2021 season. The forecast uses a deep learning algorithm to make site-specific, probabilistic forecasts at a weekly forecast range for toxin levels measured in shellfish tissue. Forecasts had high accuracy in the 2021 season, correctly predicting closure events and locations despite a highly unusual season. Stakeholders reported a positive view of the forecast system, and stakeholder input continues to be of key importance as further modifications are made to the system. There are benefits and challenges to the stakeholder-based design of the system.

How does bivalve size influence microplastics accumulation?

Microplastics (wasted plastic particles < 5 mm in diameter) are ubiquitously distributed in the marine environment. Filter-feeding and low trophic level bivalves are vulnerable to microplastics accumulation from the surrounding depositional environment, thereby threatening both ecological health and human food safety. Microplastics had been detected in lots of coastal Bivalvia species. However, the influence of biological morphology on the mechanism of microplastics accumulation is not clear. There is also a knowledge gap of which species are preferred for commercial consumption, which creates loopholes in risk identification for food safety. A survey on a commercial popular eaten but under-researched hard clam (Meretrix meretrix; Linnaeus, 1758) from a famous fishery port city in southern China was carried out to comprehensively analyze shell size influence on microplastics accumulation in bivalves and consequently, human intake risk via bivalve consumption. Detected microplastics count in per individual (MCI) was 24.64 ± 19.11 items · individual−1, and microplastics count per gram (MCG; wet weight with shell) was 0.66 ± 0.54 items · g−1. When the shell width grew by 1 mm, MCI increased by 1.01 times, but MCG decreased by 0.97 times. Dominant microplastics characteristics found in this study was fiber and fragment. Sizes ranged from 25 to 150 μm, and dark colors (black, red, and blue) were found. The mostly common polymers were polyethene (PE, 40%), polyethylene terephthalate (PET, 23%), and polypropylene (PP, 18%). Estimated annual intake (EAI) risk of microplastics via hard clam consumption by residents was 6652.26 ± 5327.28 items · year −1 · person −1. The microplastics in bivalves and EAI was relatively high. When shell width grew by 1 mm, EAI decreased by 0.97 times. Therefore, eating a fixed amount of larger hard clams with a relatively low amount of microplastics can reduce EAI risk for consumers. A systematic investigation of emission sources along main coast, where bivalve production is prominent will be useful for food safety control in this region.

The Role of Invasion Status and Taxon of Basibionts in Marine Community Structure

Studies on non-native epibionts typically focus on the organismal-level impacts of epibiosis on basibionts, rather than community-level impacts of this relationship. The purpose of our study was to evaluate if non-native basibionts in general facilitate invasions through epibiosis in Maine compared to native basibiont species. We collected 64 basibiont assemblages including replicate samples of 10 different basibiont taxa on the central Maine coast in October 2019. Each basibiont and associated epibionts were identified to genus, classified as native or non-native to the region where they were collected, and weighed. We found that while there was no association between invasion status of the epibiont and the basibiont, native basibionts had a significantly higher Shannon Diversity Index than non-native basibionts. Although diversity of epibionts was greater on native basibionts, the percentage of invaders varied across basibiont taxa. Specific basibiont taxon characteristics may be more important than status because different taxa have different surface topographies, resulting in varying settlement among epibiont species. Our study indicates that there is differential settlement of epibiont taxa across basibiont taxa, which may help predict, based on surface characteristics, which species support more epibiont taxa. This study, as a snapshot of floating dock fouling communities within a 10 km radius, may indicate that non-native basibionts play a role in changing community structure. Expanding the scope of this initial study to include a wider taxonomic and geographic range should help determine if epibiosis is truly a facilitative process in invasions.

Bold Experiments in Fish Farming: In coastal Maine, scientists and seafood workers are cleaning up aquaculture's dirty reputation and trying to save a threatened economy-but not without controversy.

Bold Experiments in Fish Farming: In coastal Maine, scientists and seafood workers are cleaning up aquaculture's dirty reputation and trying to save a threatened economy-but not without controversy.

SEALNET: Facial recognition software for ecological studies of harbor seals.

Methods for long‐term monitoring of coastal species such as harbor seals (Phoca vitulina) are often costly, time‐consuming, and highly invasive, underscoring the need for improved techniques for data collection and analysis. Here, we propose the use of automated facial recognition technology for identification of individual seals and demonstrate its utility in ecological and population studies. We created a software package, SealNet, that automates photo identification of seals, using a graphical user interface (GUI) software to detect, align, and chip seal faces from photographs and a deep convolutional neural network (CNN) suitable for small datasets (e.g., 100 seals with five photos per seal) to classify individual seals. We piloted the SealNet technology with a population of harbor seals located within Casco Bay on the coast of Maine, USA. Across two years of sampling, 2019 and 2020, at seven haul‐out sites in Middle Bay, we obtained a dataset optimized for the development and testing of SealNet. We processed 1752 images representing 408 individual seals and achieved 88% Rank‐1 and 96% Rank‐5 accuracy in closed set seal identification. In identifying individual seals, SealNet software outperformed a similar face recognition method, PrimNet, developed for primates but retrained on seals. The ease and wealth of image data that can be processed using SealNet software contributes a vital tool for ecological and behavioral studies of marine mammals in the developing field of conservation technology.

Volcanism of the Late Silurian Eastport Formation of the Coastal Volcanic Belt, Passamaquoddy Bay, New Brunswick

This field trip is an excursion through the exquisite, nearly pristine exposures of a Silurian, felsic-dominated bimodal volcanic and sedimentary sequence exposed in the Passamaquoddy Bay area of southwestern, New Brunswick (Eastport Formation). These rocks form the northwest extension of the Coastal Volcanic Belt that extends from southwestern New Brunswick to the southern coast of Maine. The sequence is significant because it is part of a large bimodal igneous province with evidence for supervolcano-scale eruptions that began to form during the close of the Salinic Orogeny (about 424 Ma), and continued into the Acadian Orogeny (421–400 Ma). The geochemical characteristic of the rocks can be explained by extension related volcanism but the specific drivers of the extension are uncertain. The Passamaquoddy Bay sequence is 4 km thick and comprises four cycles of basaltic-rhyolitic volcanism. Basaltic volcanism typically precedes rhyolitic volcanism in Cycles 1–3. Cycle 4 represents the waning stages of volcanism and is dominated by peritidal sediments and basaltic volcanics. A spectrum of eruptive and emplacement mechanisms is represented ranging from the Hawaiian and Strombolian-type volcanism of the basaltic flows and pyroclastic scoria deposits, to highly explosive sub-Plinian to Plinian rhyolitic pyroclastic eruptions forming pyroclastic density currents (PDC) and high grade rheomorphic ignimbrites. During this field trip we will examine key exposures illustrating this spectrum of eruptive and emplacement processes, and their diagnostic characteristics, along with evidence for the interaction between mafic and felsic magmas and a variety of peperitic breccias formed as a result of emplacement of flows on wet peritidal sediments. The constraints the depositional setting and voluminous bimodal volcanism places on tectonic models will also be considered.

The potential socio-environmental advantages of repurposing lobster impoundments for eastern oyster (Crassostrea virginica) aquaculture

Tidal impoundments have been used for centuries to enhance aquaculture production worldwide. Here, we examine the potential for lobster pounds, tidal impoundments common to Maine, USA, and Atlantic Canada, to serve as boundary objects that bridge the gap between the fishing and aquaculture industries. Proponents of coastal-economic diversification have heralded aquaculture as a means of creating new revenue streams for the working waterfront, thus increasing resilience to socioeconomic and environmental disruptions. However, various barriers to entry have thus far led to little crossover between the fishing and aquaculture communities in the Northwest Atlantic. Lobster pounds are uniquely positioned to overcome these barriers as (1) pounds are usually located near traditional lobster landing locations and integrated within existing seafood distribution systems, (2) pounds are typically owned by fishing communities or cooperatives and can thus be permitted for aquaculture with relative ease, and (3) pounds have historically been used to store and cultivate economically important marine species. To assess the spatial potential and validate repurposing lobster pounds for eastern oyster (Crassostrea virginica) aquaculture lease sites offer comparable if not advantageous growth to standard oyster farms, we compiled the location and size of all known pounds in Maine and tracked oyster growth and surface temperature over two growing seasons both within and outside a lobster pound. We documented 87 pounds representing approximately 1 km2 along Maine's coast, a potential 15% increase in bivalve lease acreage if all were converted to aquaculture. Oysters held within the study pound reached market size in two growing seasons. We also identified multiple weeks in which the shell lengths of oysters inside the pound were significantly greater than those outside. These growth differences were correlated with greater surface temperatures inside the pound. We suggest that pounds are potentially positioned to both provide environmentally suitable spaces for oyster growth and remove barriers to enter the aquaculture industry.

Who’s Silenced? Who’s Not?

Abstract This essay juxtaposes two stories of Indigenous-settler “first contact” in the twenty-first century. One describes an event of community-based research in coastal Maine in summer 2000; the other describes an event of community-based confrontation at the Serpent Mound earthworks site in Ohio on the winter solstice 2020. The stories overlap and intersect in surprising ways, and they prompt unresolved questions about the function of “American” literary criticism at the present time: What actually happens when Indigenous voices enter the structures of the settler academy? Who benefits, and whose interests are ultimately served? Within current conventions, is it possible to center Indigenous knowledges and research agendas, to address the pressing concerns of Indigenous communities? And what does it mean to pursue scholarship ostensibly focused on aspects of Indigenous cultures within social and political contexts that continue to allow or even to promote the settler erasure of Indigenous claims—not only to distant or recent histories but to ongoing presence? Is it enough for academic institutions to assume a neutral stance on such issues? Or are “Americanist” scholars obligated to pursue more rigorous forms of disrupting settler business as usual?

Role of Mafic Replenishments in the Geochemical Evolution of the Deer Isle Granite, Coastal Maine

Role of Mafic Replenishments in the Geochemical Evolution of the Deer Isle Granite, Coastal Maine

Impacts of COVID-19 on Tourism in Bar Harbor, Maine

This paper examines the effects of COVID-19 on tourism in Bar Harbor, Maine. The analysis considers four channels by which the pandemic affected Bar Harbor: (1) reduction in overnight visitors, (2) decrease in Acadia National Park users, (3) cancellation of the 2020 cruise ship season, and (4) a national effect related to trends in overall US restaurant sales. The relative impacts of these four factors on Bar Harbor restaurant sales varied widely by month: the reduction in overnight tourists explains 40 percent of the overall decline; the national effect is associated with 35 percent of Bar Harbor’s decline; the cancellation of all cruise ship visits in 2020 explains 11 percent; and the reduction in the number of Acadia National Park users is responsible for 14 percent of the decline in restaurant sales in 2020. Knowing more about the channels by which COVID-19 affected hospitality sales in Bar Harbor can help state and local officials with recovery efforts and support tourism along the Maine coast.

Application of a Bayesian hierarchical model to estimate trends in Atlantic harbor seal (Phoca vitulina vitulina) abundance in Maine, U.S.A., 1993–2018

AbstractThe population of harbor seals (Phoca vitulina vitulina) along the coast of Maine, U.S.A., has experienced rapid growth in abundance following passage of the Marine Mammal Protection Act in 1972 but current information on trends in abundance is lacking. In this study, we apply a Bayesian hierarchical model to aerial survey data of nonpups and pups. Prior to 2001, estimates of growth rates from 8‐year moving averages reached a high of 2.1% and 9.4% per year with posterior probabilities of positive growth of .97 and &gt;.99 for nonpups and pups, respectively. Between 2001 and 2012, estimated growth rates for nonpups decreased to a low of −1.9% per year with a posterior probability of negative growth of .95. Between 2012 and 2018, posterior estimates of growth were close to zero suggesting little change in abundance of nonpups. Estimates of growth for pups were close to zero between 2001 and 2012 but reached a low of −2.5% per year with a posterior probability of negative growth of 0.94 at the end of the time series suggesting a decrease in pup abundance between 2012 and 2018. The total abundance estimate for 2018 is 61,336 (CV = 0.08).

Maine’s Mode of Privateering: A Tale of Fraud and Collusion in the Northeast Borderlands, 1812–1815

The American declaration of war passed by Congress in June 1812 was followed by a prize act which authorised the issuing of Letters of marque. These commissions or licenses allowed American citizens to fit out privately armed vessels to seize British ships. Although most privateers complied with Congress’s instructions, their counterparts operating along the Maine coast used their commissions to further own economic self-interest by orchestrating pre-arranged captures with British merchants in Nova Scotia and New Brunswick. Since the British government encouraged its subjects to trade with the enemy to undermine the American war effort, American privateers assumed most of the risks. Merchants and mariners from as far away as New York and Connecticut traveled to Maine to trade with the British despite the hazards of detection. As these privateers engaged in fraud, other Americans turned to vigilante violence to uncover and foil these schemes. After the British occupied Eastern Maine in the summer of 1814 trading with the enemy became illegal on the British side of the border. Despite the risks, British merchants continued to engage in trade with the enemy. Ultimately, persistence of conflict and accommodation in the Northeastern Borderlands, the area comprising Maine, Nova Scotia and New Brunswick, helped undermined Eastern Maine’s allegiance to the United States.

Model estimated baseflow for streams with endangered Atlantic Salmon in Maine,USA

AbstractWe present a regression model for estimating mean August baseflow per square kilometer of drainage area to help resource managers assess relative amounts of baseflow in Maine streams with Atlantic Salmon habitat. The model was derived from mean August baseflows computed at 31 USGS streamflow gages in Maine. We use an ordinary least squares regression model to estimate mean August baseflow per unit drainage area from two explanatory variables: percentage of the basin underlain by sand and gravel aquifers and mean July precipitation in the basin. This model provides the ability to estimate mean August baseflow in cubic meters per second per square kilometer of basin area on user‐selected, ungaged sites throughout Maine south of 46° 21′55″ N latitude. The model has an adjusted R2of 0.78 and a mean 95% prediction interval of plus or minus 0.002 cubic meters per second per square kilometer. A map of the Narraguagus watershed in eastern coastal Maine shows reaches color coded by relative amounts of baseflow predicted by the model as an example of how this method could be applied throughout Maine. The map can be used to identify reaches with relatively higher amounts of baseflow during summer low flows for habitat conservation and restoration work. These areas have the potential to be high‐quality habitat for Atlantic salmon and other cold‐water fish because baseflows are known to moderate stream temperatures in summer low‐flow periods.

A quantitative assessment of spatial patterns of socio-demographic change in coastal Maine: one process or many?

Coastal regions are experiencing socio-demographic shifts that have local, regional, and even wider implications for coastal management and planning. These shifts can arise from different local geographic drivers. This paper considers different change processes and undertakes a quantitative analysis to investigate potential drivers and geographic variations in coastal change processes. We use coastal Maine as the study region and employ multivariate methods using American Community Survey 5-year estimate period data. We first address the question: is there a coastal effect? Secondly, we conduct a cluster analysis to identify spatial variations in processes that may be at work over the extent of the coast. Thirdly, we conduct a change analysis to identify where socio-economic and demographic shifts are occurring most rapidly. Our analysis contributes to the understanding of comparative and quantitative analysis of change processes in a coastal setting that may be variously categorized as amenity migration, counterurbanization, suburbanization, or touristification depending on geographic context. Comparative results show clear separation between coastal and non-coastal communities on several individual indicators. The K-means cluster analysis reveals multivariate differentiation among the group of coastal communities. The ranked change analysis indicates differentiation among the coastal group, pointing toward potential differentiation in processes driving these changes.

Investigating Pseudo-nitzschia australis introduction to the Gulf of Maine with observations and models

In 2016, an unprecedented Pseudo-nitzschia australis bloom in the Gulf of Maine led to the first shellfishery closures due to domoic acid in the region's history. In this paper, potential introduction routes of P. australis are explored through observations, a hydrodynamic model, and a Lagrangian particle tracking model. Based on particle tracking experiments, the most likely source of P. australis to the Gulf of Maine was the Scotian Shelf. However, in 2016, connectivity between the Scotian Shelf and the bloom region was not significantly different from the other years between 2012 and 2019, nor were temperature conditions more favorable for P. australis growth. Observations indicated changes on the Scotian Shelf in 2016 preceded the introduction of P. australis: increased bottom salinity and decreased surface salinity. The increased bottom salinity on the shelf may be linked to anomalously saline water observed near the coast of Maine in 2016 via transport through Northeast Channel. The changes in upstream water mass properties may be related to the introduction of P. australis, and could be the result of either increased influence of the Labrador Current or increased outflow from the Gulf of St. Lawrence. The ultimate source of P. australis remains unknown, although the species has previously been observed in the eastern North Atlantic, and connectivity across the ocean is possible via a subpolar route. Continued and increased monitoring is warranted to track interannual Pseudo-nitzschia persistence in the Gulf of Maine, and sampling on the Scotian Shelf should be conducted to map upstream P. australis populations.

U–Pb zircon geochronology and implications of Cambrian plutonism in the Ellsworth belt, Maine

The Ellsworth belt is one of several fault-bounded blocks exposed along the southeastern coast of Maine that formed within Ganderia. New ID-TIMS U–Pb geochronological data integrated with field relationships provide additional insights into the timing of magmatism and deformation in the Ellsworth belt. The deformed Lamoine Granite was selected for U–Pb zircon analysis to: (i) establish the protolith age; (ii) provide direct temporal constraints on regional low-grade metamorphism and deformation; and (iii) elucidate relationships between the Ellsworth belt and coeval rocks elsewhere in the Appalachian orogen. The Lamoine Granite was emplaced within the Ellsworth Schist at 492 ± 1.7 Ma; this is the first unequivocal evidence for a Furongian magmatic event in the Ellsworth belt. The schistosity in the Lamoine Granite is parallel to the main fabric of the host Ellsworth Schist and provides a maximum estimate for timing of the regional metamorphic overprint. Widespread deformation in the Ellsworth belt where kinematic indicators indicate a top-to-northwest sense of shear is attributed to thrusting during which progressive horizontal shortening, caused crustal thickening and peak greenschist facies metamorphism. The Cambrian U–Pb age permits correlation of the Lamoine Granite with the Cameron Road Granite in the Annidale belt of New Brunswick where subduction-related magmas intruded the Penobscot arc–back-arc and were subsequently deformed during the Penobscot Orogeny.

Bacterial transfer from Pristionchus entomophagus nematodes to the invasive ant Myrmica rubra and the potential for colony mortality in coastal Maine

SummaryThe necromenic nematode Pristionchus entomophagus has been frequently found in nests of the invasive European ant Myrmica rubra in coastal Maine, United States, and may contribute to ant mortality and collapse of colonies by transferring environmental bacteria. Paenibacillus and several other bacterial species were found in the digestive tracts of nematodes harvested from collapsed ant colonies. Serratia marcescens, Serratia nematodiphila, and Pseudomonas fluorescens were collected from the hemolymph of nematode-infected wax moth (Galleria mellonella) larvae. Virulence against waxworms varied by the site of origin of the nematodes. In adult nematodes, bacteria were highly concentrated in the digestive tract with none observed on the cuticle. In contrast, juveniles had more on the cuticle than in the digestive tract. Host species was the primary factor affecting bacterial community profiles, but Spiroplasma sp. and Serratia marcescens sequences were shared across ants, nematodes, and nematode-exposed G. mellonella larvae.