OUR PROJECTS

Growing Bay Scallops on a Maine Oyster Farm as a Strategy to Diversify Crops and Adapt to a Warming Gulf (2023-2024)

This project aimed to test whether bay scallops (Argopecten irradians) could be grown in rapidly-warming Maine waters as a crop-diversification strategy on a subtidal oyster farm. Our approach used techniques that were developed to grow bay scallops in their traditional range and techniques that have been used to grow sea scallops locally. 

Scallop seed (1mm) was grown in lantern nets (first in spat bags, then loose) from July 2023 until December 2024. Staring at month ten, scallops were stocked at 75 individuals per lantern net tier. Lantern nets were dried on a specially designed raft to prevent and removing fouling, while reducing the amount scallops were handled for cleaning.

The majority of scallops (79%) reached a marketable size by the 15th month of growth. Mortality was high and predominantly driven by unusually severe fouling by mussels during the overwinter off-season. During months of normal operation, regular drying on the custom rafts prevented most fouling.

Only 46% of scallops remained at the end of the experiment. These scallops were very positively received by buyers, fetched a high price, but required a large amount of labor to process.

READ OUR FULL REPORT HERE

Field Testing the Viability of 3D-printed Oyster Farm Equipment (2022-2023)

    This project aimed to test whether 3D printed and computer routed materials were able to withstand the harshness of the marine environment and the rigors of farming. Though the end goal was to enable the fabrication of prototypes/new designs, this project tested a standard piece of equipment to separate the suitability of materials from the strengths/weaknesses of new designs

    Professional fabricators attempted to replicate commercial oyster growout bags using extrusive 3D printing, laser cutting, and CNC routing. Of these techniques, only CNC routing produced viable bags. Bags made of three different materials were tested: high density polyethylene (HDPE), very-high molecular weight polyethylene (VHMW), and polyethylene terephthalate glycol (PETG).

    Bags were deployed with on a commercial oyster farm and on an educational aquaculture lease and were checked for damage and fouling from June of 2022 until June of 2023.

    Bags constructed from VHMW saw the least damage of the materials tested- averaging 1 instance of damage per bag compared to 1.6 instances of damage per bag for HDPE and 3.4 instances of damage per bag for PETG. None of the VHMW had a structural failure compared to 13% of HDPE bags and 43% of PETG bags.

    The fabrication techniques used in this project were both time consuming and expensive for objects of this scale. Though there is promise for custom fabrication of aquaculture equipment using CNC routing and 3d printing, it does not seem practical (even for prototypes) until the technology advances.

READ THE FULL REPORT HERE

Quahog Clam and American Oyster Polyculture (2017-2021)

   This project tested crop diversification on existing oyster farms through the addition of a high-value crop species with different environmental needs (quahog clams). The pilot trial of this grow-out system has been run at Winnegance Oyster Farm starting in 2017 and has tested at three additional farms as a part of a grant funded collaboration with Manomet.

   This system has the potential to increase crop yields without increasing farm footprint, produces a product with different susceptibility to disease and market conditions, and could provide large quahog seed for municipal shellfish programs and wild harvesters.

   Current work is focused on the determining effects of site/environmental conditions, improving nursery technique and pre-harvest handling, and identifying market opportunities.

2017 Project Report

2018 Project Report

Collaborative work with Manomet

Maine explores potential for farming higher-value clam

Aquaculture North America, March 2020

Are littleneck clams the next frontier in aquaculture?

Portland Press Herald, May 2018

Funded by Northeast SARE and the national Seagrant program, in partnership with Manomet

Crop Shading to Prevent Algal Biofouling (2019)

    The removal of fouling is one of the greatest sources of labor on an oyster farm. Colonization of oyster farming equipment by algae and invertebrates reduces crop growth rates and can increase mortality. To address this problem many shellfish farmers have adopted floating cage designs that allow for periodic air drying as a fouling control. Though highly effective for controlling soft-bodied invertebrates (such as tunicates, worms, and larval forms of shellfish), it is much less useful for controlling macroalgae, which have evolved to tolerate periodic drying at low tides. Fouling by macroalgae can pose unique problems on a shellfish farm. It is quick-onset, fast growing, heavy/difficult to handle, resistant to common cleaning techniques, and can lead to the settlement of other fouling organisms.

    The natural distribution of many macroalgae are highly light dependent (with species tied to a specific depth and light-period). This project used cage-shading as a means to prevent algal colonization of oyster cages by introducing dark conditions unfavorable to algal growth. Opaque-panel shades were highly effective at both preventing and removing algal fouling. Crop shading provides an environmentally-friendly, passive, and prophylactic approach to mitigating algal bio-fouling that has the potential to benefit all shellfish farmers using floating-cage systems, as well as other ocean-users and noise-sensitive wildlife.

Full report HERE

Funded by Northeast SARE (Sustainable Agriculture Research and Education)