Oyster Basics 101

Oyster Basics 101PANGEA SHELLFISH COMPANYMAY 2015 | WWW.PANGEASHELLF ISH.COM

Topics Covered Biology

◦ Species◦ Life Cycle

Aquaculture◦ Growth Methods◦ Our Growing Process

Industry◦ Trends◦ Concerns

Edible Oysters 7 commercially edible oyster species

◦ Eastern Oyster -- Crassostrea virginica◦ Pacific Oyster -- Crassostrea gigas◦ Kumamoto Oyster -- Crassostrea sikamea◦ Belon Oyster -- Ostrea edulis◦ Olympia Oysters -- Ostrea lurida or Ostera conchapila◦ Portuguese Oysters – Crassostrea angulata◦ Sydney Rock Oysters -- Saccostrea glomerata

*Not the same as pearl oysters

Available at Pangea

About the Edible Oyster Scientific Classification

◦ Animalia > Mollusca > Bivalvia

Anatomy◦ Filter feeders

◦ Feeds on plankton & algae in water◦ Can filter up to 1 gallon an hour

◦ Abductor muscle keeps shell closed◦ Hermaphrodites

◦ Change sex depending on life stage and season

◦ Spawn during the summer◦ Triggered by water temperature◦ Can release up to 100 million eggs per female

Oyster Aquaculture Sustainable source of seafood

◦ Oysters are farmed in the ocean, its natural habitat

Wild oysters are limited◦ Overfishing led to dwindling numbers e.g. Chesapeake Bay◦ Wild fisheries only open seasonally◦ Regulations on catch limits and harvest periods

2013 NOAA Fisheries report valued landings at $218 million◦ Pacific region leads in production◦ Industry could be much larger since report

Wild vs. farmed oysters◦ Each has own advantages and not necessarily better than the other

Farming Oysters1. Growers buy seed (juvenile oysters) from hatcheries

◦ Seed can be purchased at different sizes◦ Some growers collect wild spat to cultivate

2. Seed is nurtured and tended until it reaches market size◦ Typical market size for Eastern oyster ~3”◦ Market size for Pacific oyster varies

3. Grade and cull oysters for size and quality

4. Clean, bag, and ship to distributors and restaurants

Growout Methods

Growout methods greatly influence look and even taste

◦ Methods vary depending on the local environment

The Shigoku is a Pacific Oyster like the ones on the right, but because it has a different growout method, the look and shape is very different.

Growout Methods Bottom-culture

◦ Oysters grow out on the ocean bottom◦ Natural growout like wild oysters◦ Advantages: produces hearty and strong shells◦ Disadvantages: losses due to suffocation, predation, weather, etc.

Off-bottom culture◦ Oysters never touch the ocean bottom◦ Advantages: keeps oysters protected and no losses◦ Disadvantages: weak shell growth

Off-bottom Methods

Cage-cultured Tray-cultured Rack-and-bag

Surface-culture (i.e. bags or trays float on water

surface)

Suspended-culture (i.e. bags or trays hang or

suspended in the ocean)

Growing Process on Standish Shore Oyster FarmDUXBURY, MASSACHUSETTS, USA

Every May, we buy about 3 million oyster seed graded at 2mm.

We place the seed in our upweller, a nursery system that pumps plankton-rich water through each silo to “force-feed” the oysters. The oysters should double in volume every few days.

The oysters are graded for the first time at 6mm. Once they reach this size, they continue to grow in bags and cages out in the bay.

During their growth period throughout the summer, the oysters are tumbled to promote consistent and strong shells. Our tumbler also grades the oysters with the holes in its metal screens.

In the fall, the oysters reach 1.5-2.5” and are ready for winter hibernation. No new growth occurs in the winter. Some growers store their oysters in coolers or long line them to the ocean bottom. In Duxbury, many bottom-plant their oysters and hope they will survive through the winter.

The bottom-planted oysters will grow until the following fall when they reach 3” or larger.

When the oysters are ready the following fall, we harvest them by hand picking, raking, or dragging a rake across the bottom with a boat.

In its final stages, the oysters are hand culled for quality and size, purged on the farm to spit out any mud, and bagged to be sold!

Industry Trends Oysters are experiencing a renaissance

◦ Used to be cheap and eaten by working class◦ Oyster market becoming the wine market

◦ “Terroir” to wine as “merroir” is to oysters◦ Marketing and branding allowing more niche players

◦ Raw bars opening across the country

Farm-to-table movement◦ Emergence of small local oyster farms◦ Rise in consumer interest – e.g. oyster farm tours

A new loss leader in restaurants◦ Draw customers in with oyster happy hours and make margin on drinks◦ Restaurants feel the urge to jump on the bandwagon

Industry Concerns Growing oyster consumption also means more shellfish illnesses

◦ Vibrio parahaemolyticus◦ Bacteria that lives in the ocean◦ Causes illness when high amounts are consumed◦ Multiplies in warm conditions

◦ Regulations burden smaller farms

Mislabeling and seafood fraud

Environmental Impacts◦ Water acidification and environmental changes◦ Algae blooms, red tides, and closures put pressure on supply especially in summer

◦ Gulf oysters affected by BP oil spill◦ Chesapeake still recovering from overfishing

◦ Oyster farming is becoming more industrial◦ http

://www.seattletimes.com/seattle-news/environment/dept-of-ecology-growers-cancel-pesticide-permit-affecting-oysters-2/

For more information…Contact Us

Pangea Shellfish Company314 Northern Avenue

Boston, MA 02210

(617) 439-4999sales@pangeashellfish.com

Visit our website at www.pangeashellfish.com or sign up for our newsletter to receive more info on

interesting shellfish topics.