designing a marine protected area from the bottom up: a synthetic approach to benthic habitat...
TRANSCRIPT
-
7/30/2019 Designing a Marine Protected Area from the Bottom Up: A synthetic approach to benthic habitat mapping in the S
1/19
Designing a Marine Protected Area from the Bottom Up
A synthetic approach to benthic habitat mapping in the San Juan Islands
Luis Camilli
Center for Habitat Studies
Moss Landing Marine Laboratories
8272 Moss Landing RoadMoss Landing, CA 95039-9674
mailto:[email protected]:[email protected] -
7/30/2019 Designing a Marine Protected Area from the Bottom Up: A synthetic approach to benthic habitat mapping in the S
2/19
Abstract
Bathymetric mapping and groundtruthing techniques were combined in a
Geographical Information System (GIS) to produce benthic habitat maps of the San Juan
Islands of Washington State. Multibeam SONAR data for Griffin Bay and surrounding
channels was collected in a collaborative effort between the Canadian Hydrographic
Survey and Moss Landing Marine Laboratories Center for Habitat Studies in April of
2005. Analysis of Remotely Operated Vehicle surveys, sediment grab samples, and
multibeam backscatter analysis were combined with ancillary biological studies from the
region in consideration of Griffin Bay as a potential location for a Marine Protected Area.
IntroductionManagement of individual species without considering larger ecosystem
dynamics upon which they depend is a common criticism of species management plans
(Ward et al. 1999). Ecological processes and critical habitats are not distributed
homogeneously; hence reserve networks must be designed on the basis of spatially
explicit quantitative data (Sala et.al. 2002). Furthermore, spatial and temporal scales of
biological activity in aquatic systems are often tightly coupled to scales of physical
phenomena such as thermoclines, currents, or gyres (Steele 1989). While there are many
ecological and oceanographic factors to consider in designing an effective Marine
Protected Area (MPA), general assumptions of a bottom up approach to habitat
modeling predict benthic topological complexity as a good surrogate for benthic habitat
complexity and species diversity (Ardron et. al. 2002).
-
7/30/2019 Designing a Marine Protected Area from the Bottom Up: A synthetic approach to benthic habitat mapping in the S
3/19
Ecological hierarchy theory assumes that scale interdependencies are hierarchical,
in that processes at one scale create patterns at another scale (Levin 1992). This
paradigm also maintains that wider or coarser scales approximate the boundary
conditions of narrower or finer scales by constraining the behavior and dynamics of the
processes occurring at finer scales (Pereira 2002).
This study applies a holistic synthesis of micro scale resolution (
-
7/30/2019 Designing a Marine Protected Area from the Bottom Up: A synthetic approach to benthic habitat mapping in the S
4/19
areas for managing coastal marine biological diversity. (Ward et.al. 1999) In order to
accurately describe and effectively apply the ecological and biological attributes of
underwater habitat and to facilitate comparison between scientific disciplines, a deep
water classification scheme has been developed to describe and communicate
geophysical data that is collected remotely (Green et.al. 1999).
Study Area
Regional Geography and Geology
Located in the Puget Sound of Washington state, the San Juan Islands form a
geologically complex province surrounded by the Cascade Mountains, Vancouver Island,
and the Olympic Peninsula (Fig 1). A compound assemblage of early Paleozoic through
Eocene rock defines the physiography of the San Juan Islands and can be represented by
two main blocks separated by the Haro fault (Johnson & Whetten). During the
Pleistocene the Strait of Juan de Fuca probably evolved as the result of a combination of
both tectonic and glacial process. Rapid retreat of glacial continental ice and high
isostatic rebound occurred between 13,600 and 11,300 years Before Present (Dethier
1995). The San Juan Archipelago is bounded by Rosario Strait to the east, Haro Strait to
the north and west, and the Strait of Juan de Fuca to the west and south. The archipelago
is composed of 176 islands, San Juan, Orcas, Lopez and Shaw Islands being the largest.
Intermittent sand and cobble beaches lead to deep glacier scoured channels ,often
exceeding 100 meters in depth, with extreme tidal currents (up to 7 knots) predominating.
Regional MPAs
-
7/30/2019 Designing a Marine Protected Area from the Bottom Up: A synthetic approach to benthic habitat mapping in the S
5/19
In response to declines in rockfish populations, the San Juan County Marine
Resource Committee (MRC) was created in 1996 and established eight Voluntary No
Take Zones in 1998. Currently in the San Juan Islands, MPAs consist mainly of rocky
habitat designed as refuges for rockfishes, lingcod, and other rocky habitat fishes. This
may not be suitable for species such as clams or other invertebrates which use soft
sediments for habitat. Since then Washington Department of Fish and Wildlife has
instituted 15 statutory marine reserves in Puget Sound designed to protect bottomfish,
shellfish, or intertidal invertebrates from non-tribal harvest with some areas having
Salmon, Herring and Crab excepted from the rule (NOAA 2002). Nationally, Marine
Protected Areas (MPAs) were established by Executive Order (E.O.) 13158 on May 26,
2000.
Griffin Bay
Griffin Bay (480 30 0 N, 1230 00 W) is located on the east side of San Juan
Island, in the San Juan Island Archipelago of Puget Sound. Since 1960, Friday Harbor
Sand and Gravel (FHSG) has been located on Jacksons beach on the northern shoreline
of Griffin Bay. Mining operations ceased in 1999.
MethodsA 14 meter hydrographic research vessel, the Otter Bay, was used to collect
multibeam SONAR data for Griffin Bay and surrounding channels in April of 2005 in a
collaborative effort between the Canadian Hydrographic Survey and Moss Landing
Marine Laboratories Center of Habitat Studies.
-
7/30/2019 Designing a Marine Protected Area from the Bottom Up: A synthetic approach to benthic habitat mapping in the S
6/19
Equipment
The Otter Bay was equipped with a hull mounted Kongsberg SIMRAD EM3000
multibeam echo sounder operating at 300 kHz with 127 beams and 1.5 degree beam
width. The effective depth for this instrument is 1 meter to 250 meters with 100 %
coverage. The sensor array also provided a nearfield sidescan emulation using
multibeam backscatter intensity with 5 centimeter resolution. Time Variable Gain was
adjusted automatically using an EM 3000 dynamic Moving Vessel Profiler (MVP).
Conductivity Temperature Depth (CTD) casts were performed twice during the survey to
verify acoustic calibrations of the MVP. Tidal height was measured each day from a
datum on the station dock to synchronize the multibeam system with local tidal
oscillations.
Analysis
Analysis and processing of acoustic multibeam SONAR data was conducted with
Caris HIPS and SIPS Version 5.4 software to create a 0.5 meter grid. Backscatter was
analyzed to verify indurations of substrate. Bathymetry was imported into ArcGIS
version 9.0 Geographical Information System and georectified to a WGS 1984 datum and
a Universal Transverse Mercator projection. A benthic habitat map, using a classification
scheme developed at the Center for Habitat Studies at Moss Landing Marine Laboratories
(Green et.al. 1999), was created based on interpretation of bathymetry, backscatter,
video drop cameras, and sediment samples (Fig. 3).
A second map of species assemblages was prepared for use as a heuristic in
designing a potential MPA for Griffin Bay. Bathymetry, backscatter, ROV video
analysis, and ancillary maps and biological data collected from the area were
incorporated in a synthetic manner to create a map for use by resource managers and
-
7/30/2019 Designing a Marine Protected Area from the Bottom Up: A synthetic approach to benthic habitat mapping in the S
7/19
biologists (Fig 4). ROV tracklines from a 2004 survey in Griffin Bay were plotted on the
habitat map and analyzed for species presence/absence. The ROV data also served as a
guide for groundtruthing additional areas not surveyed in 2004. A sediment grab was
used in conjunction with a tethered drop camera (which was deployed from a smaller, 5-
meter vessel) to interpret ambiguous or noisy bathymetric and backscatter data.
Results
Corroborative data
Rocky Habitat
The bathymetry of North Griffin Bay shows large aggregations of complex,
differentially eroded bedrock that is very rugose and of hard induration. Studies from the
area indicate the potential for an area like this to be excellent habitat for Rock fish
species. For example, Copper (Sebastes. caurinus), quillback (S. maliger), and brown
rockfishes (S. auriculatus) prefer high relief rocky habitats, while Lingcod (Ophiodon
elongatus) and kelp greenling (Hexagrammos decagrammus) are more generalists,
preferring a wider range of substrates and being less dependent on complexity and relief
factors than rockfishes (Pacunski and Palsson, 2001). Other fish species using North
Griffin Bay areLepidopsetta bilineata (Rock sole), Pleuronectes vetulus (English sole),
Platichthys stellatus (Starry flounder) and Syngnathus griseolineatus (Bay pipefish).
(Rodgers 2002).
Analysis of the 2004 ROV video showed these same rocky areas to be highly
prolific not only in terms of Sole and Rockfish species, but also heavily encrusted with
sessile invertebrates like mytridium, anemones, tube worms, scallops, clams and motile
invertebrates such as echinoderms, gastropods, and even a giant cephalopod (octopus).
-
7/30/2019 Designing a Marine Protected Area from the Bottom Up: A synthetic approach to benthic habitat mapping in the S
8/19
A study from the University of Washington, Friday Harbor Laboratories suggests that
North Griffin Bay is also a nursery area for four species of shrimp Pandalus danae,
Pandalus goniurus, Pandalus platyceros and Crangon spp. (Rodgers 2002).
Soft substrate habitat
Dungeness crabs are a major part of recreational and commercial fisheries of the
Pacific Northwest. Crab pots were abundant during the Griffin Bay survey in shallow
areas near a 10 meter isobath (personal observation) and during video transects.
Estimates from a University of Washington survey in South Griffin Bay found high
densities of Helmet crabs (Telmessus cheiragonus) and high densities of Dungeness crabs
(Cancer magister) in a range of vegetation and at all depths. (Raaum 2000). Video
analysis of 2004 ROV data from South Griffin Bay supports this. Dungeness crabs,
which are known to burrow in sandy bottoms and eelgrass beds, were observed in context
with dense aggregations of burrows in the soft unconsolidated sediments (mostly silt and
sand). This sediment is probably also serving as habitat for shrimp, mussels, small crabs,
clams, and worms which are the Dungeness crabs major food source.
In general, the bathymetry collected for South Griffin Bay shows a significant
change from the rocky high relief areas of North Griffin Bay changing to soft sediment.
An interesting phenomenon is that the crab fishing area is almost uniquely defined by a
long scarp feature (5 meter high wall) that is believed to be a paleoshoreline most likely
from the last ice age, and perhaps recently an active fault (Greene, pers. com). Subbottom
seismic profiling or core samples would help to verify this features origin and relation to
other regional fault systems.
-
7/30/2019 Designing a Marine Protected Area from the Bottom Up: A synthetic approach to benthic habitat mapping in the S
9/19
Vegetation:
Heterogeneity of vegetation types maybe important for MPAs. One study
examining kelp beds of Puget Sound in the Strait of Juan de Fuca found that substrate
plays a critical role in defining the understory community and that the greater substrate
diversity ofNereocystis beds offered a broader array of habitat types, and resulted in
higher numbers and species of invertebrates (Shaffer 1998). Our video analysis and the
results of the 2004 ROV survey showedLaminaria species common in most of Griffin
Bays rocky habitat surveyed. This coincides with a previous study indicating that large
Laminarian species dominate during spring and summer with a shift to fleshy red algae
during winter months (Shaffer 1998). The rocky substrate that is ubiquitous in North
Griffin Bay is probably providing the necessary attachment sites for the kelp holdfasts.
Other species observed from the video were dense patches of substory red alga
along with encrusting and geniculate corraline algae. South Griffin Bay had the most
extensive high-density eelgrass beds and may explain why it is such a prolific source for
crab fishing.
Currents and larval supply
Griffin Bays proximity to the San Juan Channel indicates another important
characteristic of its location. In Puget Sound, upwelling zones do not exist, but other
oceanographic features such as tidal gyres, tidal pumps, wind forcing, and estuarine
circulation may be significant to the success of marine refuges (Palsson 2001).
A drift card study of localized surface current circulations in the Puget Sound
showed that the San Juan channel near Griffin Bay may be an important site for larval
recruitment by functioning as a major collection zones for buoyant particles and imply
-
7/30/2019 Designing a Marine Protected Area from the Bottom Up: A synthetic approach to benthic habitat mapping in the S
10/19
the existence of a counter-clockwise circulation around the archipelago resulting from
ebb tidal eddies formed in the southern lee of the San Juan Archipelago (Klinger &
Ebbesmeyer 2001). This is important because larvae of many species (e.g., rockfish,
echinoderm, and decapods) spend long periods in the plankton and consequently their
recruitment into nearshore habitats will depend on larval behavior and on local and
regional surface circulation patterns (Allison et al. 1998; Strathmann 1987).
The effect of deep currents on the benthic substrate was evident in analysis of
bathymetric data from this survey which showed scouring predominant near rocky areas.
ROV video analysis and sediment grabs indicate these heavily scoured areas are mostly
coarse sand or shell hash (coquina). Other areas near the center of Griffin Bay and in the
San Juan Channel revealed large sand waves sometimes exceeding five meters. Lingcod
were observed in the depressions of these large sand waves and may be using the leeward
areas as a respite from the fast currents (Gunderson pers. com). The biological effects of
these strong currents on the benthic and demersel assemblages in this area need to be
investigated further.
Griffin Bay MPA?
Marine reserve boundaries are difficult to define because of inadequate
knowledge of biological diversity (i.e. species, habitats, ecosystems and ecological
processes) and difficult to defend in the face of multiple competing demands like
fisheries, mineral industries, recreation and geopolitical interests (Ward et al. 1999).
Although ecological information provides a better heuristic for conservation efforts,
conservation decisions will most likely be made in context of economic and political
-
7/30/2019 Designing a Marine Protected Area from the Bottom Up: A synthetic approach to benthic habitat mapping in the S
11/19
interests. It is therefore appropriate to analyze Griffin Bay as a potential Marine
Protected Area from both perspectives.
Data presented from this study indicates that Griffin Bay is operating as a unique
mesoscale ecological structure because two major systems exist within a relatively small
area. These are essentially a deep water, highly complex, fish and invertebrate
assemblage in North Griffin Bay, and a sediment infaunal seagrass assemblage in South
Griffin Bay. The fact that these two communities are contained within one bay
eliminates much concern for resource managers of deleterious edge effects resulting
from habitat fragmentation.
Economic benefits are considerable for the crabbing industry because of South
Griffin Bays potential as a source for other areas (both larval and trophic) for Dungeness
crab and associated species. Since North Griffin Bay is thought to be a nursery for many
invertebrate species and obligate rockfish species, this will help to bolster fishing in
surrounding areas (sinks) by acting as a buffer to fishing pressure. Economically, Griffin
Bay is also important to tourism given its proximity to Friday Harbor, a major ferry port
and holiday destination. Finally, Griffin Bay is situated near the University of
Washingtons Friday Harbor Laboratories which could utilize Griffin Bay as an
ecological benchmark to monitor and decouple short term natural variability from
regional anthropogenic change.
-
7/30/2019 Designing a Marine Protected Area from the Bottom Up: A synthetic approach to benthic habitat mapping in the S
12/19
ConclusionsA Scottish mathematician once figuratively said a map is not the territory.
Indeed maps, in the literal sense, are simply another way to represent the externalities and
phenomena of our world. A synthetic approach to understanding complex underwater
ecosystems is often required when multiple criteria and constraints intersect. Use of
acoustic imaging and a bottom up approach combined with ancillary information
conceptualized through GIS is one such way to model underwater habitats for ecological
applications. These habitat maps of the San Juan archipelago were created for use as
tools to guide resource management in the short term and ultimately to help elucidate
larger scale, and longer period oceanographic and ecological processes.
-
7/30/2019 Designing a Marine Protected Area from the Bottom Up: A synthetic approach to benthic habitat mapping in the S
13/19
AcknowledgementsThanks to Dr. Gary Greene for organizing this unique collaborative effort between Moss
Landing Marine Laboratory Center for Habitat Studies and The Canadian Hydrographic
Survey. Our gratitude to Ron and Cathy MacDowell and a grant from the Sea Doc
Society for funding this project and facilitating in so many ways. It was a pleasure
working with the Canadian hydrographic research team Kalman Czotter, Knut Lyngberg
and Gordon Allison in collecting the high resolution bathymetric data on the Otter Bay.
Thank you, Brian Dieter for your outstanding teaching and assistance. Thanks also to Dr.
Don Gunderson of the University of Washington Friday Harbor Laboratories, and Dr.
Wayne Palsson of Washington Department of Fish and Wildlife for input, ideas, and
auxiliary data that was incorporated into this habitat survey.
-
7/30/2019 Designing a Marine Protected Area from the Bottom Up: A synthetic approach to benthic habitat mapping in the S
14/19
Literature cited
1. 2000. Executive Order 13158. Pages Vol. 65 in.2. Ardron, J. A., Jennifer Lash, Dana Haggarty. 2002. Modeling a network of
Marine Protected Areas for the central coast of BC. Version 3.1. Living Oceans
Society, Sonintula, BC, Canada.
3. Bargmann, G., Thomas Jagielo , Wayne Palsson, Kurt Stick, Wallace Farron.2003. Washington contribution to the 2003 meeting of the Technical Sub-
Committee (TSC) of the Canada-US Groundfish Committee. in T. Jagielo, editor.,
Sitka, Alaska.
4. Dethier, D. P., Pessl, Fred Jr., Keuler, R.F., Balzarini, M.A., Pevear, D.R. 1995.Late Wisconsinan glaciomarine deposition and isostatic rebound, northern Puget
Lowland, Washington. GSA Bulletin 107:1288-1303.
5. Greene, G. H., Mary M. Yoklavich, Richard Starr, Victoria Connell, W. WaldoWakefield, Deidre Sullivan, James McRea Jr., Gregor M. Cailliet. 1999. Aclassification scheme for deep seafloor habitats. Oceanologica Acta 22.
6. Johnson, S. Y., Robert A. Zimmermann, Charles W. Naeser, John T. Whetten.1986. Fission-track dating of the tectonic development of the San Juan Islands,
Washington. Canadian Journal of Earth Science 23:1318-1330.
7. Klinger, T., and Curtis Ebbesmeyer. 2001. Using oceanographic linkages to guideMarine Protected Area network design. School of Marine Affairs and Friday
Harbor Laboratories, University of Washington.
8. Levin, S. A. 1992. The problem of pattern and scale in ecology. Ecology 73:1943-1967.
9. Miller, B. E. 2002. Population estimates and habitat types of bottom fish assessedby a remotely operated vehicle (ROV) around the San Juan Islands, Washington.
University of Washington, Friday Harbor.
10.NOAA. 2002. National Oceanic and Atmospheric Administration Office of Oceanand Coastal Resource Management. in.
11.Palsson, W. A. 2001. The development of criteria for establishing and monitoringno-take refuges for rockfishes and other rocky habitat fishes in Puget Sound.
Washington Department of Fish and Wildlife.
-
7/30/2019 Designing a Marine Protected Area from the Bottom Up: A synthetic approach to benthic habitat mapping in the S
15/19
12.Pereira, G. M. 2002. A typology of spatial and temporal scale relations.Geographical Analysis 34.
13.Raaum, J. 2000. The effect of habitat on fish and crab species abundance,diversity and size in temperate coastal marine communities. Friday Harbor
Laboratories, University of Washington.
14.Rodgers, K. L. 2002. Survey of nearshore soft bottom demersal fish, shrimp andcrabs in North Griffin Bay, San Juan Island, Washington. Fish 492 Undergraduate
research apprenticeship University of Washington, Friday Harbor, Washington.
15.Sala, E., Octavio Aburto-Oropez, Gustavo Paredes, Ivan Parra, Juan C. Barrera,Paul K. Dayton. 2002. A general model for designing networks of marine
reserves. Science 298.
16.San Juan County, M. R. C. 1998. Marine Reserve Bottomfish Recovery Program.in San Juan Nature Institute.
17.Shaffer, J. A. 1998. Kelp bed habitats of the inland waters of western Washington.Washington Department of Fish and Wildlife Puget Sound Research 1998.
18.Steele, J. H. 1989. The ocean "landscape". Landscape Ecology 3:185-192.19.Trnka, H. 2000. Mapping of Marine Vegetation. University of Washington,
Friday Harbor, Washington.
20.Ward, T. J., M.A. Vanderklift, A.O. Nichollis, R.A. Kenchington. 1999. Selectingmarine reserves using habitats and species assemblages as surrogates for
biological diversity. Ecological Applications 9:691-698.
21.Zajac, R. N., Ralph Lewis, Larry Poppe, David Twichell, Joseph Vozarik, MaryDiGiacomo-Cohen. 2000. Relationships among sea-floor structure and benthiccommunities in Long Island Sound at regional and benthoscape scales. Journal of
Coastal Research 16:627-640.
Personal Communication:
1. Don Gunderson School of Aquatic and Fisheries Sciences, University ofWashinton [email protected]. Gary Greene Center for Habitat Studies, Moss Landing Marine [email protected]
3. Wayne Palsson Washington Department of Fish and [email protected]
mailto:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]:[email protected] -
7/30/2019 Designing a Marine Protected Area from the Bottom Up: A synthetic approach to benthic habitat mapping in the S
16/19
Figure 1
Satellite photo of San Juan Archipelago
Courtesy of Gulf Islands National Park
-
7/30/2019 Designing a Marine Protected Area from the Bottom Up: A synthetic approach to benthic habitat mapping in the S
17/19
Figure 2
Griffin Bay sunshaded 2 meter grid bathymetry
-
7/30/2019 Designing a Marine Protected Area from the Bottom Up: A synthetic approach to benthic habitat mapping in the S
18/19
Figure 3
-
7/30/2019 Designing a Marine Protected Area from the Bottom Up: A synthetic approach to benthic habitat mapping in the S
19/19
Figure 4