Recipient Organization
SPRINGTIDE SEAWEED, LLC
14 FACTORY RD
GOULDSBORO,ME 046074222
Performing Department
(N/A)
Non Technical Summary
The green sea urchin is a valuable species of edible urchin found in northern Pacific and Atlantic oceans. Sea urchins are prized for their uni, which is present inside the shell of the urchin as five gonadal lobes, unique organs that function to both produce gametes for reproduction and to store nutrients. Uni has a rich, buttery texture, and slightly sweet, mildly briny flavor, making it a prized seafood delicacy, and one of the most valuable seafood products in the world. However, wild fishery landings have declined in the US in the past few decades, decreasing nearly 99% from 14 million pounds landed in 1993 to just over half a million pounds in 2024 in Maine. The global increasing demand for high quality uni and diminishing wild resource presents an opportunity for aquaculture, especially in Maine where there is existing seaweed aquaculture and urchin fishery infrastructure to support the new crop.As macroalgal herbivores, sea urchins can be fully integrated into a seaweed aquaculture operation, utilizing farmed seaweed in all aspects of sea urchin production, from broodstock development, to hatchery and seed production, grow out, and harvest. Springtide Seaweed proposes to develop reliable hatchery systems for production of high quality native green urchin seed, determine growth rates and uni quality of farmed urchins raised on seaweeds, and develop integrated seaweed and sea urchin aquaculture farm models to produce high quality, consistent, high-value sea urchins for uni markets.The development of new integrated seaweed and sea urchin aquaculture models will support and strengthen domestic seafood production and competitiveness, increase economic prospects and employment, and cultivate the potential of our ocean's natural resources. The development of improved hatchery techniques utilizing macroalgal cultivation methods will create commercial availability of seed urchins for the wild fishery and aquaculture industries. Culture techniques could introduce new opportunities to support the urchin industry as a whole by providing options for farming, enhancement of wild caught urchins for increased quality and value, or re-seeding wild harvest populations to increase fishing success.
Animal Health Component
45%
Research Effort Categories
Basic
10%
Applied
45%
Developmental
45%
Goals / Objectives
Goal: To create an integrated macroalgal and sea urchin farm model that utilizes cultivated macroalgae at all stages of green sea urchin cultivation for consistent reliable production of juvenile seed urchins and high qualtiy uni.Objectives:Objective 1: Improve Broodstock and Hatchery Techniques for Juvenile Urchin Seed Production1a. Develop on-farm broodstock protocols utilizing macroalgal feed that will produce viable broodstock for in-season spawning1b. Test land-based accelerated broodstock conditioning techniques to produce viable broodstock for out-of-season spawning1c. Improve hatchery production by integrating macroalgae to improve larvae development, competence, settlement, and juvenile development.Objective 2: Determine Growth and Maturity of Cultivated Sea Urchins fed Cultivated Seaweeds. Determine growth, roe consistency, quality, and seasonality for farmed urchins fed on cultivated kelp and dulse.Objective 3: Integrate seaweed feed systems into urchin farm designs
Project Methods
Methods:Objective 1: Improve Broodstock and Hatchery Techniques for Juvenile Seed Production1a. Develop on-farm broodstock protocols utilizing macroalgal feed that will produce viable broodstock for in-season spawning.Determine broodstock conditioning methods by testing pre-spawning enhancement in cages at sea. Feed cultivated kelp ad libitum before spawning in the hatchery. Determine reproductive quality and quantity every other month by measuring urchin size test diameter and weight, and reproductive output by stimulating gamete release, and measuring expelled sperm and eggs, also mixing together and sampling for percent fertilization. Initiate two separate gamete releases for larval rearing, one in January, and one in February, using hatchery processes, and determine reproductive success and seed production through the larval and settling processes. Reproductive success will be measured through broodstock urchin size and weight, gamete release including color, egg size, and volume, halo formation, larval development through microscopic observation daily, and sample competence, settlement, and recruitment counts.1b. Test land-based accelerated broodstock conditioning techniques to produce viable broodstock for out-of-season spawningDevelop accelerated broodstock enhancement in tanks at the hatchery for earlier hatching. Select the largest cultivated urchin stock on the farm for broodstock development (>52mm diameter), place in a tank in a walk-in environmental chamber with controlled variables oflight, photoperiod, and temperature, to reflect a "Constant Spring" condition, photoperiod 12 L:12 D, temperature of 6 °C. Feed cultivated kelp ad libitum feeding regime starting in July before initiating spawning in the hatchery in November. Determine reproductive quality and quantity every other month by measuring urchin size, weight and reproductive output by stimulating gamete release and measuring expelled sperm and eggs, also mixing together and sampling for percent fertilization, determined by number of halos developed over eggs after introduction of sperm, per sea urchin hatchery protocols. With the remaining urchins, initiate gamete releases in November, December, and January determine reproductive success and seed production through the larval and settling processes. Reproductive success will be measured as described in (1a).1c. Improve hatchery production integrating macroalgae to improve larvae development, competence, settlement, and juvenile development.New improvements to the hatchery method will be tested at the Springtide facility, including; more stringent temperature control of environmental chambers (10°C), lower densities, and an increased water exchange rate. Instead of raising larvae on primarily the microalgae species Dunaliella salina, hatchery runs will utilize microalgal cultures of Dunaliella tertiolecta, Chaetoceros calcitrans, Rhodomonas sp, and Phaeodactylum tricornutum, utilizing 0.2micron filtered and uv sterilized water for all larval and microalgal cultures. Once larval cultures reach competence, they will be settled into tanks prepared with natural biofilm and juvenile sugar kelp and dulse plants that will have been prepared 1-2 months in tanks prior to larval settlement. Instead of utilizing horizontal polycarbonate wavy plates for settlement surfaces, we will trial a staggered stacked plate formation centered around central rods. In addition, we will settle larvae onto tufted tank-raised dulse plants (Palmaria palmata) cultivated at Springtide Seaweed, which have been suitable settlement substrates in previous studies.Objective 2: Determine Growth and Maturity of Cultivated Sea Urchins fed Cultivated SeaweedsDetermine growth for farmed urchins fed on cultivated kelp and dulse. Set up a series of cages of urchins each to be fed either cultured sugar kelp (Saccharina latissima) or dulse (Palmaria palmata) or a 50/50 mixture of both ad libitum. Sample each monthly for test diameter and weight. Determine growth rates and any seasonal difference in growth. Track temperature with hobo data loggers, farm effort, and feed intake. Compare to a control of three cages that are not fed. Determine roe consistency, quality, and seasonality by sampling harvestable size urchins monthly to determine roe quality, consistency, and quality during typical harvest season. Monthly sample urchins from each set of cages for reproductive quality and quantity by measuring urchin size, weight, and gonad color, volume, flavor, and quality. Gonads will be removed from each animal and weighed (G), and gonad index calculated by gonad index (GI) = G/WW × 100. Roe color, flavor, and texture will be estimated categorically by ranking, with ranked gonad color values in three classes, corresponding to commercial grades (Class A: 1-yellow, 2-yellow-orange, 3-orange, Class B: 4- light brown, 5-orange brown, Class C: 6-rust, 7-dark brown; Ranked texture data: Index range from 1=smooth to 5= coarse; Ranked Flavor Data: Pleasant/unpleasant and taste/aftertaste categories, with descriptions; Odor: Pleasant/unpleasant categories, with descriptions), with at least 2 or more tasters. Sugar kelp will be cultivated on the Springtide farm, and Dulse will be cultivated in tanks at the hatchery, and on the farm, with all seed produced at the Springtide seaweed nursery.Objective 3: Integrate seaweed feed systems into urchin farm designsTrial kelp dropper lines for feed production. Dropper lines could be integrated onto longlines with suspended urchin cages for a more versatile feed production model for urchins. Seed dropper lines with sugar kelp, and dropper lines with dulse in the Springtide nursery, out-plant on farm in fall by suspending from horizontal long line near urchin cages. Also seed growing modules with kelp and dulse and suspend on longlines near urchin cages. Track growth, yield, quality, fouling, and water temperature monthly from droppers and growing modules.Evaluation: Progress of project will be evaluated with monthly reviews of project activities, data organization, and analysis. Final project review and reporting will synthesize findings and develop a whole-farm model for sea urchin seed production and grow out utilizing farmed seaweeds. Further plans will be made with program developments for commercialization.