Jul 1, 2015

Maine DMR rebuffs National Marine Fisheries Service on intertidal cod habitat

Amazing interchange
First the recent  letter from the National Marine Fisheries service about the importance of intertidal fish habitat. Then the response by Pat Keliher of Maine DMR casting doubt.   Apologies for incomplete re-editing of the text!

National Oceanic and Atmospheric Administration 
National Marine Fisheries Service
55 Great Republic Drive Gloucester, MA 01 930-2276

Patrick Keliher Commissioner
Division of Marine Resources
21 State House Station Augusta, ME 04333-0021

Re: State of Maine Rockweed Working Group and Fisheries Management Plan

Dear Mr. Keliher
We have reviewed the Maine Department of Marine Resources Fishery Management Plan (FMp) for Rockweed (Ascophyllum nodosum) implemented January 2014, and have been following the deliberations of the Rockweed Working Group that has been tasked with setting criteria for establishing "no take" areas along the Maine coastline.

We appreciate and commend your efforts to proactively establish a fishery management plan as the rockweed harvest industry appears to be on a rapidly increasing trajectory in Maine. Further, we acknowledge that the harvest management strategy of maintaining a minimum of l6" cutting height above the algal holdfast and recommended measures to limit the total biomass take allocations are representative of sustainable fishery management tools.

We are most interested in the development and implementation of the "no take,' areas since the protection of this macroalgal species has the potential to provide significant habitat value for managed fish species. As such we offer the following comments for youi consideration. Habitat Value of Rockweed As described in the Rockweed FMP, intertidal areas that support Ascophyllum growthconsist of rocky substrates from mid to lower intertidal coastal waters.

The FMP recognizes that this particular species of Ascophyllum is a dominant, major component of the rocky intertidal habitat along the Maine coast, especially within bays and estuaries.

Further, in Section vi., Ecology, of the FMp, the role intertidal rockweed plays in providing forage areas during periods of high tides for fish species is described. In our view, the FMP could provide additional information regarding the role intertidal zones play in providing juvenile fish species refuge from predation, and the importance of these areas in mediating the spatial distribution and survivorship ofjuvenile fish species.

Intertidal and inshore subtidal rocky habitats with added habitat complexity provided by macroalgal cover serve as important shelter and forage habitat for a variety of species including Atlantic cod, pollock, ocean pout, red hake, white hake, windowpane flounder, striped bass, cunner, tautog, and lobster. It is well established that intertidal zones serye as areas of refuge from predation anã foraging habitat for juvenile fish during periods of high tide (Helfman et al. 2009).

 Of particular concern is the juvenile life history stage for Atlantic cod. As you are awaÍe, we issued an update on the stock assessment for Gulf of Maine (GOM) Atlantic cod on August 7,2014. The indicators of stock condition for GOM cod have declined orworsened in20l3, and the spawning stock biomass levels are estimated to be at 3 to 4 percent of the biom *o'-** o, 'ooo target for maximum sustainable yield with biomass at all-time lows. The results of this stock assessment lead to the implementation of Emergency Gulf of Maine Cod Management Measures on November 13,2014.

Given the state of the GOM cod stock, it is essential to conserve as well as minimize adverse impacts to habitats that can support and increase survivorship of critical life stages for this stock. Juvenile Atlantic cod utilization of the intertidal zone has been well documented throughout their range in the northwestern Atlantic and within Maine coastal waters (Ojeda and Dearborn 1990, Moring 1993). Juvenile cod exhibit diel activity patterns within intertidal habitats, and this activity pattern differs based on juvenile age.

Age-O+ and age-l Atlantic cod are found in greater numbers within the intertidal zone at night, and young-of-the-year (age-O) utilize intertidal areas more frequently during the day (Methven and Bajdik 1994, Gran| and Brown 1998, Anderson et aI.2007). This shift in diel activity pattern is also found in subtidal habitats where separation of spatial distribution patterns based on age has been recorded and is attributed to conspecific predation ofage- 0 juveniles by age-l+ juveniles (Grant and Brown 1998, Gotceitas and Brown 1993, Gotceitas et al. 1995 and 1997, Ãnderson et al.2007, Theodorou 2013).

It was also found that there were significantly different spatial distribution patterns and shoaling behavior differences in juvenile cod based on habitat complexity (Grant and Brown 1998, Gotceitas and Brown 1993, Gotceitas et al. 1995 and 1997, Anderson 2007). Multiple studies have demonstrated that despite the potential that juvenile cod may initially settle to the substrate indiscriminately, age-O+ juveniles are more abundant in complex habitats (e.g. rocþ or vegetated habitats), whether this is due to active movement of post-settlement juvenile cod into complex habitats or due to higher survivorship rates in complex habitats is unknown (Lough et al., 1989, Gotceitas and Brown 1993, Fraser et al. 1996, Gotceitas et al. 1997, Grant and Brown 1998, Linehan et al. 2001, ).

The mark-recapture study conducted by Grant and Brown (1998) found a level of site fidelity exhibited by the age-O+ juvenile cod sampled indicating that once settled into complex habitat juvenile cod maintain a level of residency within that habitat.

The structural complexity of rocky substrates with attached macroalgal and macrofauna have been demonstrated to: 1) mediate the spatial distribution ofjuvenile cod, and 2) provide additional refuge from predation that significantly increases survivorship ofjuvenile cod over barren rocky and sand habiøts (Fraser ef al. 1996, Gotceitas et al. 1997 , Lindholm et al. 1999 and 2001).

In a laboratory study, Lindholm et al. (1999) found that juvenile cod survivorship was significantly higher in cobble substrates with dense, emergent coverage compared with smooth cobble and cobble with a low density of emergent coverage. Multiple field studies have demonstrated that juvenile cod occur with higher abundances in rocky habitats with macroalgal coverage versus bare rocþ substrates (Keats et al.1987, Gotceitas etal.1997, Cote et al.2004,Lazzari and Stone 2006).

While the relative abundance and survivorship ofjuvenile cod has not been directly studied inAscophyllum dominated intertidal habitats, the laboratory and field studies that have been conducted suggestthat higher density macroalgal intertidal rocky habitats would support more abundant populations ofjuvenile cod and significantly mediate juvenile survivorship over lower density macroalgal intertidal rocky habitats. Rockweed Working Group As discussed above, we believe that rockweed covered rocky intertidal and subtidal areas play an important role as habitat for managed fish species, particularly juvenile Atlantic cod.

We strongly support consideration by the Rockweed Working Group, of the importance and use of this habitat in I the establishment of criteria for designating "no take" areas and the potential benefits for Atlantic cod and other species from such designations.

We look forward to continued coordination in the implementation of the Rockweed FMP and Rockweed Working Group's development of "no take" area criteria.
Please contact Alison Verkade at978-281-6266 or alison.verkade@noaa.gov if you would like to discuss this further.

Assistant Re gional Administrator for Habitat Conservation co: Chris Vonderweidt, Chair RWG Tom Nies, NEFMC David Preble, NEFMC Kevin Madley, PRD.
References Listed below


Maine DMR's  response  letter

Dept of Marine Resources
21 State house Station
 Augusta ME

June 1, 2015

Louis A. Chiarella
Assistant Regional Administrator for Habitat Conservation
National Marine Fisheries Service
55 Great Republic Drive
Gloucester, MA 01930
Dear Mr. Chiarella,
1 am writing in response to your letter of March 31, 2015 "Re: State of Maine Rockweed Working Group and Fisheries Management Plan." Your letter states that rockweed is of significant habitat value to juvenile Atlantic cod and requests designation of no take zones along the coast. The request is predicated on an understanding that the Rockweed Fishery Management Plan (FMP) and current efforts to develop no—harvest conservation areas are in response to a ‘“rapidly increasing trajectory" of the rockweed fishery. It references several peer reviewed studies to demonstrate how rockweed has been
proven as significant juvenile cod habitat.

The Department of Marine Resources (DMR) first became involved in creating the Rockweed FMP in late 2012 at the request of the Maine Seaweed Council (MSC)—an industry group created to maintain a sustainable seaweed resource in Maine. The MSC approached me because they wanted to develop a
management framework to ensure that Maine’s seaweed fisheries would continue to be harvested in a sustainable manner. As a proponent of FMP’s, 1 directed Dr. Linda Mercer and Chris Vonderweidt of my staff to attend MSC meetings and assist with the development of a seaweed FMP. My hope was that
their end product would include management recormnendations that DMR could implement through rulemaking. DMR eventually took over FMP development in 2013 following legislative approval of a DMR submitted bill (LD 585) that proposed development of a seaweed FMP. The initial seaweed FMP
focused on rockweed only, because rockweed landings comprise over 95% of Maine’s seaweed harvest.

Rockweed has been harvested in Maine for over 40 years and landings are not on a rapidly increasing trajectory as your letter states. The total annual harvest is less than 1% of the coastwide biomass, while natural processes remove 34-50% annually. Only a fraction of rockweed is sold fresh or raw because
unprocessed rockweed brings a relatively low boat price compared to other fisheries. Value must be added through processing into concentrated fertilizers or nutraceuticals. A significant increase in landings is unrealistic and could not happen quickly because processing capabilities are fmite, which
limits the demand for rockweed.

A key question for the Rockweed Working Group’s (RWG) analysis is whether rockweed is a keyhabitat component. lf rockweed is not a key habitat component for a sensitive species then closures to protect that species would be unnecessary and inappropriate. The section of your letter titled "Habitat
Value of Rockweed" is pertinent to this question because it suggests that studies have shown how
rockweed covered rocky intertidal areas play an important role as habitat for juvenile Atlantic cod.
However, the majority of literature that is referenced in your letter has little or no relevance to intertidal macroalgae or juvenile cod utilization of rockweed.

For example, the Habitat Value of Rockweed section of your letter states "Juvenile Atlantic cod utilization of the intertidal zone has been well documented throughout its range in the northwestem Atlantic and within Maine coastal waters (Ojeda and Dearbom 1990, Moring 1993)". The referenced
studies are Diversity, abundance, and spatial distribution of fishes and crustaceans in the rocky subtidal zone ofthe Gub"of Maine by Ojeda and Dearbom and Checklist ofthe tidepoolfishes of Maine by Moring. Ojeda and Dearbom’s study site was a subtidal area devoid of macroalgae. The study site was "sloping relatively flat ledge" from 10-12 meters (33 — 40 feet) depth, "large rocks and boulders" from 12-20 meters (40 — 65 feet) depth, and “primarily sand with occasional boulders" at depth greater than
20 meters (65 feet).

Additionally, cod represented only 3.5% of intercepts. ln other words, the study area was not rockweed habitat or representative of an area that could be rockweed habitat and few cod were caught.

Dearborn’s paper focuses on fish species that were collected in studies of fish trapped in saltmarsh and
rocky intertidal tidepools during low tide. The intent of the paper as explained in the introduction is
documenting species that were collected in other studies generally (including published and unpublished
literature). As Dearborn explains, species listed on the checklist of tidepool fishes fall into one of three
categories of intertidal habitat use. "Fishes in tidepools, whether in rocky intertidal areas or in trapped
pools in salt marshes, can generally be grouped in one of three categories: (1) resident fishes using
tidepools over an extended period of the life cycle, (2) juveniles using tidepools in only the first (or
sometimes second) year of life, and (3) transient or rare visitors to tidepools that are not expected to be
encountered during successive tidal cycles. In other words, it is inappropriate to infer significant
intertidal use solely because a species was doctunented in a tidepool. That aside, cod were never
actually collected in any of the nine studies of tidepool fish that Dearbom compiled. American cod are
listed as "Potential tidepool species that have been reported intertidally in Maine waters (but not trapped
in tidepools) or in tidepools in other states".

The paragraph continues by referencing three studies on “diel activity pattems within intertidal habitats”
by Methven and Bajdik 1994, Grant and Brown 1998, and Anderson et al. 2007. However, Methven and
Badjick’s study site was the only of the three conducted in the intertidal zone and the paper makes no
mention of macroalgae or submerged aquatic vegetation (SAV). The paragraph concludes by discussing
behavioral studies conducted in the subtidal zone or laboratory, with eelgrass (Zostera marina) as the
SAV component of the study site, or having no SAV component at all.

The Habitat Value of Rockweed section of your letter concludes by discussing and referencing several
studies that have "demonstrated that juvenile cod occur with higher abundances in rocky habitats with
macroalgal coverage versus bare rocky substrates." Generally, this is an accurate assessment ofthe
results, that juvenile cod appear to prefer SAV covered substrates versus bare rocks, but the studies
provide little evidence of juvenile cod utilization of rockweed. Of the four studies that are referenced
here, Cote et al. is the only one having an intertidal study site, but the authors clearly state that “it was
therefore unclear from this study if juvenile Atlantic cod were selecting habitat on the basis of a vertical
relief or structural complexity." Lazzari and Stone investigated habitat use in four shallow water
habitats (eelgrass, Laminaria Zongicruruis (kelp), Phyllophora sp. (algae), and mud/sand) and found that
cod preferred eelgrass over other SAV. ln the discussion section, the paper notes that presence of cod
“occurred more in the Zostera tows." The authors elaborate in the discussion stating "Other published information comparing algae to other vegetated habitats also found them to be less utilized as juvenile
fish habitat."

Upon close inspection, the studies referenced in your letter present compelling information that eelgrass
(Zostera marina) is significant habitat for juvenile cod. However, it is misleading to infer that this
referenced literature supports the claim that rockweed beds are significant habitat to juvenile cod. lt is
important to understand that eelgrass is a seagrass, not a macroalgae. There are significant differences in
habitat, structure, growth, and reproduction between eelgrass and intertidal macroalgae such as
rockweed. Finally, the list of publications in your letter is not comprehensive and omits studies such as
Substrate selection and use of protective cover by juvenile Atlantic cod Gadus morhua in inshore waters
of Newfoundland by Gregory and Anderson, who conclude that "Juvenile cod did not exhibit selection
for substrates with macroalgal cover."

As explained above, the infonnation and analysis included in your letter provides insufficient
justification for the Department to promulgate rulemaking to establish no-harvest rockweed areas for
protection of juvenile Atlantic cod. As with any marine resources issue, I ani always open to
considering new and additional information if you wish to provide it. Thank you for your interest in
Maine’s marine resources.

Patrick C. Keliher

NMFS' References Listed below
 Anderson, J. L., Laurel, B. J., and Brown, J. A. 2007. Diel changes in behaviour and habitat use by age-O Atlantic cod (Gadus morhua L.) inthe laboratory and field. Journal of Experimental Marine Biology and Ecology 351(I),:267-275. Cote, D., Moulton, S., Frampton, P. C. 8., Scruton,D.A., and McKinley, R. S. 2004. Habitat use and early winter movements by juvenile Atlantic cod in a coastal area of Newfoundland. Journal of Fish Biology 64(3):665-679. Fraser, S., Gotceitas, V., and Brown, J. A. 1996. Interactions between age-classes of Atlantic cod and their distribution among bottom substrates. Canadian Joumal of Fisheries and Aquatic Sciences 53 (2):3 0 5 -3 1 4. Gotceitas, V., and Brown, J. A. 1993. Substrate selection by juvenile Atlantic cod (Gadus morhua): effects of predation risk. Oecologia 93(1): 3l-31. Gotceitas, V., Fraser, S., and Brown, J. A. 1995. Habitat use by juvenile Atlantic cod (Gadus morhua) in the presence of an actively foraging and non-foraging predator. Marine Biology 123(3):421-430. Gotceitas, V., F¡aser, S., and Brown, J. A.1997. Use of eelgrass beds (Zostera marina)by juvenile Atlantic cod (Gadus morhua). Canadian Journal of Fisheries and Aquatic Sciences 54(6):1306-13 19. Grant, S. M., and Brown, J. A. 1998. Nearshore settlement and localized populations of age 0 Atlantic cod(Gadus morhua) in shallow coastal waters of Nervfoundland. Canadian journal of fisheries and aquatic sciences 55(6): l3l7 -1327 . Helfman, G., Collette, B. B., Facey, D.E., and Bowen, B. W. 2009. The diversity of fishes: biology, evolution, and ecology. John V/iley & Sons. Keats, D. W., Steele, D. H., and South, G. R. 1987. The role of fleshy macroalgae in the ecology ofjuvenile cod (Gadus morhua L.) in inshore waters off eastern Newfoundland. Canadian Journal of Zoology 65(1): 49-53. Lindholm, J., P. J. Auster, and L. Kaufman. 1999. Habitat-mediated survivorship ofjuvenile (O-year) Atlantic cod (Gadus morhua). Marine Ecology Progress Series 180:247-255. Lindholm, J., P.J. Auster, M. Ruth andL. Kaufman. 2001. Modeling the effects of fishing and implications for the design of marine protected areas:juvenile fish responses to variations in seafloor habitat. Conservation Biology 15:424-437. Linehan, J. E., Gregory, R. S., and Schneider, D. C. 2001. Predation risk of age-O cod (Gadus) relative to depth and substrate in coastal waters. Journal of Experimental Marine Biology and Ecology 263(l):25-44. Lazzari, M. 4., and Stone, B.2.2006. Use of submerged aquatic vegetation as habitat by youngof-the-year epibenthic fishes in shallow Maine nearshore waters. Estuarine, Coastal and Shelf Science 69(3): 591-606. Lough, R. G., P. C. Valentine, D. C. Potter, P. J. Auditore, G. R. Bolz, J.D. Neilson, & R. I. Perry. 1989. Ecology and distribution ofjuvenile cod and haddock in relation to sediment type and bottom currents on eastern Georges Bank. Mar. Ecol. Prog. Ser. 56:1-12. Methven, D.4., and C. Bajdik. 1994.Temporal variation in size and abundance sfjuvenile Atlantis cod(Gadus morhara) at an inshore site off eastern Newfoundland. Can. 1. Fish. Aquat. Sci. 5l : 78-90. Moring, J. R. 1993. Check list of the tidepool fishes of Maine. Maine Naturalist: 155-160. Ojeda, F. P., and Dearborn, J. H. 1990. Diversity, abundance, and spatial distribution of fishes and crustaceans in the rocky subtidal zone of the Gulf of Maine. Fishery Bulletin S8(2): 403-410. Theodorou, P., Snorrason, S. S., and Ólafsdóuir, G. Á. 2013.Habitat complexity affects how young of the year Atlantic cod Gadus morhua perceive predation threat from older conspecifics. Journal of fish biology 82(6):2lal-2146. 

No comments: