Coastal Observing Center was established in 2002 as part of NOAA’s
Coastal Observation Technology System (COTS). It is now one of sixteen
COTS projects. The UNH Center is working to develop and implement
an observing system for monitoring the Western Gulf of Maine ecosystem.
Our goal is to implement an end-to-end system with the capability
to detect, model, and ultimately forecast changes in the ecosystem.
This Center is developing new and efficient methods to acquire, manage
and distribute data. Data are analyzed and synthesized to generate
new information, and information products are being designed to meet
the needs of stakeholders. Two stakeholder communities identified
in this region are those interested in water quality and in the fate
and variability of the near-shore fisheries. A third stakeholder community
are the formal and informal educators who help us translate knowledge
about the coastal ocean to current and future generations. We are
working closely with the Gulf of Maine Ocean Observing System (GoMOOS)
and other partners in the northeast. Our collective goal
is to establish a sustainable program of coastal ocean observations
as part of the U.S. Integrated Ocean Observing System.
The Coastal Observing Center draws upon the talents of UNH scientists
with expertise related to coastal observing and analysis. GoMOOS had
established an array of 10 buoys in 2001 that provided real-time observations
of the physical environment (currents, temperature, winds). While
such measurements are essential to an ecosystem monitoring program,
there was a need to develop new methodologies, models and analyses
that pertain directly to the ecosystem.
Our focus is on a region centered on the Piscataqua River at
Portsmouth Harbor, that extends north to the Kennebec River and south
to Cape Cod (Fig. 1). This region includes Jeffrey’s Ledge,
one of the most important fish habitats in the Gulf of Maine, now
closed to ground fishing, and the adjacent deep waters of Wilkinson
Basin. Like other coastal environments, this is a region of significant
biological productivity and complex circulation. Central factors controlling
the productivity are the seasonal cycles of water-column stratification
and nutrient uptake, and year-to-year variability in the Maine coastal
current. This east-coast site also represents a region where the surface
waters interact with advected continental air that is often polluted.
The effects of air-sea exchange of such trace chemicals on any coastal
ecosystem are largely unknown. Two phenomena that are likely to have
a measurable impact on our oceanic ecosystem are short-term episodic
events, such as storms and strong freshwater pulses from land, and
the long-term deposition of trace chemicals via the air or rivers.
These issues are being examined by our ship-based measurement program
whose goal is to provide both an ecosystem baseline and knowledge
about its variability and controls. This knowledge will inform models
that will be used to simulate what we observe, and to test hypotheses
about the mechanisms controlling the marine ecosystem in this region.
Fig. 1. The Western Gulf of Maine region of
interest (left) and its location within the Gulf of Maine.
Stations on the Coastal Transect and Wilkinson Basin Transect
are sampled once a month. The locations of GoMOOS buoys and
NDBC stations are also shown.
Field measurements are made on monthly cruises along
the two transects shown in figure 1. The Coastal Transect
visits GoMOOS buoy B and waters of the Kennebec River Estuary, and
the Wilkinson Basin Transect extends into one of the deep
basins of the Gulf of Maine. The observations are made by teams responsible
for different components of the ecosystem and its environmental controls.
All teams participate in the cruises. Data from the cruises flow into
WebCOAST, our data management system, and are being used to create
models and to develop remote sensing algorithms for our region of
While much can be learned from standard oceanographic measurements
of temperature, salinity, nutrients, and biomass concentrations of
phytoplankton and zooplankton, new technologies are being developed
for observing the ecosystem. Measurements of the underwater light
field are made with state-of-the-art instruments and used to calculate
concentrations of phytoplankton biomass (as chlorophyll) as well as
other forms of organic matter. A further step being taken is to connect
our observations to satellite remote sensing of surface winds, ocean
color and sea surface temperature to develop cost-effective means
to extend such observations in time and space. Our long-term plan
is to minimize the need for ship-based sampling by developing automated
techniques deployed on buoys and by using remote sensing methods.
However, the ability to sample and assess biological and ecological
variables currently requires water sampling with analyses conducted
in the laboratory.
An observing system for monitoring the ecosystem is approached by
posing five questions: How is the ecosystem changing? What are the
forcing factors causing it to change? How does the ecosystem respond
to natural and human forcings? Can we predict future changes? and
What are the consequences for stakeholders in our region?
How is the Ecosystem Changing and Why?
We know from historical records and from our own observations that
the timing and magnitude of phytoplankton blooms vary significantly
on interannual to decadal time scales (Fig. 2). In some years (e.g.,
2002), the spring bloom of phytoplankton occurs in April, coinciding
with vernal flowering on land, whereas in other years (e.g.,1999),
the bloom occurs in February (Durbin et al. 2003).
Continuous Plankton Recorder (CPR) data reveal that
this late-winter bloom was present throughout the 1990s but was, from
all indications, absent during the 1980s. The CPR data have also shown
dramatic shifts in the abundance of prominent zooplankton species
over the past four decades (Pershing et al. submitted). Four
of the smaller taxa were 1-3 orders of magnitude more abundant in
the 1990s than in the 1980s, whereas adults of Calanus finmarchicus
experienced a 1-2 order of magnitude decline in the 1990s.
1. The NAO is an index of the difference in the winter
surface air pressure of a low pressure system off Iceland and a high
pressure system off the Azores that typically set up in the North Atlantic
Calanus finmarchicus is the major prey of forage and other
species, including herring, mackerel, sand lance, and right whales.
In the Gulf of Maine, Calanus finmarchicus is at the southern edge
of its temperature range, and thus is vulnerable to climate-mediated
changes in water temperature. During the plankton surveys conducted
by Henry Bigelow in the early 1900s (Bigelow, 1926), Calanus finmarchicus
was observed to dominate the zooplankton assemblages. However, in
recent years, its abundance has declined in several areas within the
Gulf of Maine. Such changes have been linked to reduced calving rates
and migration patterns of right whales, and to the disappearance of
hundreds of thousands of red-necked phalaropes (right) over the past
decade in the Bay of Fundy.
Interannual variation in zooplankton species might be the result of
changes in climate. The upward trend in northern hemisphere atmospheric
temperature, attributed to the increase in atmospheric greenhouse
gases, might result in a warming of Gulf of Maine surface waters.
Recent warming trends have been seen in surface waters in Boothbay
Harbor, for example, and in the long records from the dock at Woods
Hole. Temperature change in itself may gradually or abruptly alter
species distributions, as some species, such as herring and Calanus,
at the southern edge of their range. Another climate-related reason
for interannual variation in the ecosystem might be the nature of
water that enters the Gulf through the Northeast Channel. The North
Atlantic Oscillation (NAO) is a climate-related phenomenon that affects
Arctic wind patterns and water temperature in the coastal Northwest
Atlantic, where it has been shown to affect the northern cod stock
(Drinkwater 2002). The influence of the NAO on the Gulf of Maine is
less clear, although there is evidence that in some states relatively
cold and Calanus-poor Labrador shelf water flows southward
across the Northeast Channel, where it makes its way into the deep
water of the Gulf of Maine. Interannual to interdecadal variations
in wind patterns, circulation and stratification also force ecosystem
change in the Gulf of Maine.
Effects of Rivers on the Western Gulf of Maine Ecosystem.
-- One of the ways that humans affect the marine ecosystem is through
the rivers. Large rivers are major mechanisms for nutrient delivery
to the ocean, and river water quality affects freshwater ecosystems
and oceanic food webs. Three rivers are important to the Western Gulf
of Maine Ecosystem. The Kennebec River estuary lies at the northern
edge of our study area and has been a focus of our field work for
the past two years. Discharge from this estuary mixes with the western
Maine coastal current and is carried southward, thus potentially affecting
water conditions throughout the region. The Kennebec River estuary
is formed by the convergence of the Kennebec and Androscoggin rivers.
The Androscoggin River was designated one of the ten most polluted
rivers in America in the 1960s (Mitnik 2002), and both rivers have
a history of water-quality problems. Numerous pulp and paper mills
are located along the rivers, as well as municipal wastewater treatment
facilities. Prior to the passage of the Clean Water Act in the mid-1970s,
partially treated and untreated municipal and industrial wastewater
was discharged directly into both rivers. Clean-up activities since
that time have partially restored the Andro-scoggin, and both rivers
now generally maintain fishable/swimmable status. The Androscoggin
and Kennebec rivers have been implicated in the re-occurring blooms
of “red tide” organisms, although the exact linkage remains
Two other rivers important to the Western Gulf of Maine region are
the Piscataqua and Merrimack rivers. The Piscataqua River enters the
Gulf of Maine at Portmouth Harbor, one of only two naturally deep
harbors on the U.S. east coast. Together with Little Bay and Great
Bay, it forms the Great Bay Estuary, a large, inland, tidally-dominated
system that serves as a critical breeding and nursery ground for finfish,
shellfish and invertebrates. Significant reductions in water quality
and seagrass in this estuary have been linked to increased development
since the 1970s (Short et al. 1991). The Merrimack River enters the
Gulf at Ipswich Bay, Massachusetts. It has the most densely populated
drainage basin in our domain. Many of New England’s former mill
cities (Manchester, Lawrence, Lowell, Haverhill) are located along
this river, which has a long history of pollution issues. Of this
river Henry David Thoreau (1849) wrote“Salmon, shad and
Alewives were formerly abundant here . . . until the dam, . . . and
the factories at Lowell, put an end to their migrations hitherward.
. . . Perchance, after a few thousands of years, if the fishes will
be patient, and pass their summers elsewhere . . . nature will have
levelled . . . the Lowell factories, and … River [will] run
An end-to-end system is being designed to deliver products tailored
to benefit specific user communities: fisheries stakeholders, coastal
resource managers, and educators. The benefits of to fisheries
stakeholders are information, education and advanced warning
to mitigate effects of ecosystem changes on harvesting of Gulf of
Maine resources. Coastal resource managers include
State planners, fish and game personnel, wetlands conservation staff,
estuarine reserve managers and the like. Their role is to protect
and restore natural resources in our estuarine and nearshore waters
up to three miles offshore. They have expressed a need for better
understanding of the spatial and temporal variability in water quality
parameters currently monitored, and a better understanding of the
coastal “system” of interacting riverine, estuarine, nearshore
and offshore waters. Coupled physical-biological models being developed
by our Center can be used to assess how representative the stations
now being monitored are of the whole region, and to provide a systems-level
understanding that should lead to a better sampling strategy for monitoring
water quality. To benefit formal and informal educators,
our Center has been demonstrating how to integrate ocean topics into
the existing curriculum using ocean observing data. There is a pressing
need to educate today’s citizens and future generations about
the ocean to engender a sense of stewardship of both coastal and global
2. The other is the Hampton Rhoads of Virginia. The large volume of
water exchanged by tides between the Great Bay and the Gulf of Maine
keeps the Portsmouth harbor deep and eliminates the need to dredge.