Bay scallops (Argopecten irradians) have been an important part of the economy of many gulf coast communities within the Florida Big Bend for decades. It was once abundant in all gulf coast counties of the state but beginning in the 1960s populations in many bays began to decline to levels where they are all but nonexistent. The cause of this decline has been associated with many factors including a decline in water quality, a decline in suitable habitat (sea turtle grass beds – Thalassia), and overharvesting. Most likely the cause included all of these. Since the collapse of both the commercial and recreational fishery, Gulf coast communities have been trying to address all three of the stressors above. Multiple monitoring projects are ongoing in the Pensacola Bay area and one of those is the Great Scallop Search.
The Great Scallop Search was developed by Sea Grant Agents in Southwest Florida and expanded, through Florida Sea Grant, to Northwest Florida. In each location volunteers snorkel a 50-meter transect line searching for live bay scallops, as well as monitoring the status of the seagrass habitat. Since 2015 317 volunteers have logged 634 hours surveying 407 50-meter transects in 106 grids in Big Lagoon or Santa Rosa Sound. In that time 4 live scallops have been logged, though we hear anecdotal reports of additional scallops being found in these bodies of water.
Survey Method
Volunteers select and survey one of 11 grids in Big Lagoon, or one of 55 grids in Santa Rosa Sound. Once on site, the volunteers anchor and record preliminary information on the data sheet provided. Two snorkelers enter the water and swim on opposite sides of a 50-meter transect line searching for live scallops. Any live scallop found is measured and returned. The species and density of the seagrass is recorded as well as the presence/absence of macroalgae on that seagrass. Four such transects are surveyed in each grid.
2023 Results
2023
SRS
BL
Total
Other
# of volunteers
72
No significant difference between 2022 and 2023
# of grids surveyed
8
8
16
Slight decrease from 2022. 16 of the 66 grids (24%) were surveyed.
# of transects surveyed
26
51
77
A decrease from 2022. More surveys were conducted in Big Lagoon than Santa Rosa Sound.
Area surveyed (m2)
2600
5100
7700
1.9 acres
# of scallop found
2
2
4
Four live scallops are a record for this project. It equals the sum of all other live scallops since the project began.
Scallop Size (cm)
4.5, 5.0
4.0, 4.5
Surveys with Seagrass
Halodule
5
12
17
17/21 surveys – 81%
Thalassia
8
11
19
19/21 surveys – 90%
Syringodium
0
2
2
2/21 surveys – 10%
Grass Density
100% grass
3
9
12
12/21 surveys (57%) were 100% grass
90%
1
0
1
Note: Volunteers typically select area for transects
75%
3
1
4
with a lot of grass.
70%
1
0
1
50%
3
9
12
5%
1
0
1
Macroalgae
Present
4
4
8
Absent
2
10
12
12/21 surveys (57%) had no macroalgae.
Abundant
2
2
4
Sediment Type
Mud
0
1
1
Sand
7
8
15
15/21 surveys (71%) were sandy.
Mixed
1
4
5
21 surveys were conducted covering 16 grids. 8 grids were surveyed in each body of water.
A total of 77 transects were conducted covering 7,700 m2 and four live scallops were found.
Two of the scallops were found in Big Lagoon and two in Santa Rosa Sound.
All scallops measured between 4-5cm (1.6-2”).
The number of live scallops found this year equaled the total number found over the last eight years.
Most of the transects included a mix of Halodule and Thalassia seagrass ranging from 100% coverage to 5%. The majority of the transects were between 50-100% grass. Four transects had 100% Thalassia. Three of those were in Santa Rosa Sound, one was in Big Lagoon. The diving depth of the volunteers ranged from 0 meters (0 feet) to 2.4 meters (8 feet). Macroalgae was present in 8 of the 21 surveys (38%) but was not abundant in most.
Volunteer measuring one of the four collected bay scallops in 2023 from Pensacola Bay.
Photo: Gina Hertz.
Summary of Project
Year
Volunteer
Grids Surveyed
Transects Surveyed
Live Scallops Found
2015
87
28
101
0
2016
96
31
111
1
2017
5
4
16
0
2018
20
7
32
0
2019
13
6
20
0
2020
5
2
16
1
2021
17
6
24
0
2022
74
22
87
2
2023
72
16
77
4
TOTAL
317
407
8
MEAN
35
14
45
0.4
To date we are averaging 35 volunteers each event, surveying 14 of the 55 possible grids (25%). We are averaging 45 transects each year (4500 m2), have logged 407 transects (40,700 m2) and have recorded 8 live scallops (< than one a year).
Discussion
Based on the results since 2016 this year was a record year for live scallops. Whether they are coming back on their own is still to be seen. Being mass spawners, bay scallop need high densities in order to reproduce successfully, and these numbers do not support that. The data, and comments from volunteers, suggest that the grasses look good and dense. Thalassia, a favorite of the bay scallop, appear to be becoming more abundant. This is a good sign.
Though small and few, bay scallops are trying to hold on in Pensacola Bay.
Photo: Gina Hertz
As I write this, we are in the middle of our 2023 Scallop Search, an event we do each year to assess whether the scallops in Pensacola Bay are trying to make a comeback on their own. Each year I am amazed at how popular this little mollusk is. On the day I am writing, I will be working with a marine science class from the University of Southern Mississippi driving over from Ocean Springs. This past weekend I worked with two families who trailered their boat from Enterprise Alabama to participate. Those on the eastern end of the panhandle are well aware of the popularity of this creature. Folks from all over the southeast travel there to go scalloping. Many of the locals in my area, when I am training them how to do a scallop search, tell me that they head east and go scalloping every year. Some even have condos for that week and it is a large part of their annual vacation plans. And many of the locals here would love to see them return to Pensacola Bay.
This is a creature that draws a lot of attention. But most know very little about it. They know it has small eyes and can swim – actually… I have recently found that not everyone knows they can swim. We know they like grassbeds and they can be harvested in the summer. They may have done this long enough to know the prime spots within the grassbeds to search for them – their “sweet spots”. But not much more.
So… let’s meet the bay scallop.
Volunteers conducting the great scallop search.
Photo: Molly O’Connor
Its scientific name is Argopecten irradians. It is a mollusk in the class Bivalvia and the family Pectinidae. There are numerous species, and the group is found all over the world. The greatest variety of them are from the Indo-Pacific region, and in each case, they are a popular seafood. Most can swim, though erratically – they are not Michael Phelps – and they use this ability to avoid predators such as starfish, which they can see with the set of simple eyes.
There are five subspecies of A. irradians. A. irradians irradians, known as the bay scallop, or Atlantic Bay scallop (and from here is just “the scallop”) is our local variety. It is found from Cape Cod to the Gulf of Mexico. They begin life as a microscopic egg produced during the mass spawning of the hermaphroditic parents (hermaphroditic meaning each parent can produce sperm and egg). The timing of the release of gametes is triggered by warming water and usually occurs in the late summer/early fall. This early egg stage sinks to the bottom where it remains for a few weeks before hatching.
The hatched larva remain microscopic, are transparent, resemble the parents, and are called spat. The spat become part of the plankton in local estuaries but eventually return to the grass in what is called “spatfall” where they attached to the seagrasses using byssal threads. They continue to grow, eventually release from the grass, and become the scallops we all know and love. Many species of scallops can live over 20 years, but our local one only lives for one.
As most know, adult scallops have two shells (bivalves) connected at the hinge on the dorsal side of the animal. Though they do add weight to the shell, a disadvantage for a swimmer, the “ribs” provide a sturdier shell. The two shells are connected by a single, large adductor muscle, which is used to open and close the valves during swimming. It is this adductor muscle we eat when consuming scallops.
Like all bivalves, scallops are filter feeders but unlike most bivalves they lack siphons to draw water in and out of the digestive tract. Rather they lie with their valves slightly gaped and allow water to pass over them. Plankton is collected by a mucous layer and then moved to the gut by cilia (small hair-like structures) where it is digested.
Bay Scallop.
Photo: FWC
Like all bivalves, scallops lack a brain as we know it but rather function using a series of ganglia (groups of nerve cells) connected to a nerve ring. These ganglia can control movement of the muscle, gills, eyes, and are connected to a statocyst, which tells the scallop how it is oriented in the water column.
There are numerous eyes aligned along the edge of each valve that can detect movement and shadows. It is believed that they use their eyes to detect potential predators and possibly initiate the swimming behavior they are famous for.
Living only one year, and reaching maximum size in late summer during spawning, scallop harvesting is regulated to that time of year in Florida. Once common from Pensacola to Miami, they are now only found in large numbers in the Big Bend region. Due to the loss of scallops in other areas, many visit the Big Bend each year to go scalloping, putting heavy harvest pressure on those stocks. There have been efforts to try and enhance the existing populations as well as restore historic ones. Here in Pensacola Bay, Florida Sea Grant works with volunteers to monitor the water quality and seagrasses, as well as assess how the few existing scallops are doing.
For more information on panhandle scallops, contact your local Sea Grant Agent at the county extension office.
The Florida Fish & Wildlife Conservation Commission and UF/IFAS Extension – Florida Sea Grant have partnered to implement an innovative community-driven effort to restore scallop populations, and we need your help! “Scallop Sitter” volunteers are trained to assist in Bay, Gulf and Franklin Counties. The goal of the program is to increase scallop populations in our local bays. Scallop sitters help reintroduce scallops into suitable areas from which they have disappeared.
Volunteers manage predator exclusion cages of scallops, which are either placed in the bay or by a dock. The cages provide a safe environment for the scallops to live and reproduce, and in turn repopulate the bays. Volunteers make monthly visits from June until December to their assigned cages where they clean scallops (algal and barnacles can attach), check mortality rate and collect salinity data that helps us determine restoration goals and success in targeted areas.
1. Click on the “reserve a spot” to select the county you are participating in.*You must provide your name, contact information and date of birth to secure an FWC permit for your cage!
2. You will be sent a registration survey via email (closer to the scallops, cage & supply pickup date or you may fill out a survey onsite) , view the virtual training link: https://myfwc.com/research/saltwater/mollusc/bay-scallops/sign-up/
and you’ll receive an invite to our Panhandle Scallop Sitter Facebook Group.
DEADLINE for steps 1 & 2 are May 25th!
3. Pick up your scallops, cage & supplies!
Pickup Information (all times local)
St. George Sound Volunteers
Date: Thursday, June 1st
Time: 10:00 AM – 1:00 PM
Location: FSU Coastal & Marine Lab (across the canal – see road signage)
3618 US-98, St. Teresa, FL 32358
St. Joseph Bay Volunteers
Date: Thursday, June 8th
Time: 10:00 – 1:00 PM
Location: St. Joseph Bay State Buffer Preserve Lodge
3915 State Road 30-A, Port St. Joe, FL 32456
St. Andrew Bay Volunteers
Date: Thursday, June 16th
Time: 10:00 AM – 1:00 PM
*We know issues happen from time to time with scallop populations. It’s a bummer. If you loose a significant amount of scallops early in this year’s program, we will do our best to accommodate our volunteers with a “second wave” scallop stocking event in August. Also, looking for other ways to help our program? We plan to offer cage building workshops in the fall, stay tuned!
¿Está interesado en hacer algo que beneficie a su comunidad marina local? ¡Disfruta de días al sol, como un “Scallop Sitter” (cuidador de las vieiras)!
“Scallop Sitters” (cuidador de vieiras) es uno de nuestros programas de voluntariado cooperativo con Pesca y Vida Silvestre de Florida (FWC, por sus siglas en inglés). Históricamente, las poblaciones de vieiras de la bahía eran muy numerosas y podían sustentar las pesquerías en muchas bahías del norte de Florida, incluidas la bahía de San Andrés, la bahía de San Juan y el Puerto de los Caimanes (Condado de Franklin). Años consecutivos de malas condiciones ambientales, pérdida de hábitat y “mala suerte” en general resultaron en una escasa producción anual y provocaron el cierre de la pesquería de vieiras. La vieira de la bahía es una especie de corta vida que pasa de ser una cría a adultos que desovan y muere en un año aproximadamente. Las poblaciones de vieiras pueden recuperarse rápidamente cuando las condiciones de crecimiento son buenas y pueden disminuir drásticamente cuando las condiciones de crecimiento son malas.
En 2011 se presentó la oportunidad de poner en marcha la restauración de las vieiras de la bahía del norte de Florida. Con la financiación del derrame de petróleo de Deepwater Horizon, se propuso un programa de restauración de vieiras en varios condados, que finalmente se estableció en 2016. Los científicos de Pesca y Vida Silvestre de Florida (FWC, por sus siglas en inglés) utilizan vieiras criadas en criaderos, obtenidos a partir de progenitores o reproductores de las bahías locales, para cultivarlas en masa y aumentar el número de adultos reproductores cerca del hábitat crítico de las praderas marinas.
La Pesca y Vida Silvestre de Florida (FWC, por sus siglas en inglés) también creó otro programa en el que los voluntarios pueden ayudar con la restauración llamado “Scallop Sitters” en 2018 e invitó a UF/IFAS Extension a ayudar a dirigir la parte de voluntarios del programa en 2019, lo que llevó a esfuerzos específicos en los condados del Golfo y la Bahía.
Para ayudar a las vieiras, los “Scallop Sitters” trabajan con UF/IFAS Extension, Florida Sea Grant y los científicos de restauración de la Pesca y Vida Silvestre de Florida (FWC, por sus siglas en inglés) limpiando las vieiras y comprobando la salinidad una vez al mes desde junio hasta enero. Foto de Tyler Jones, UF/IFAS Extension y Florida Sea Grant.
Después del hiato de 2020 debido a COVID-19, el programa presumió de casi 100 voluntarios para la campaña de 2021. UF/IFAS Extension se asocia de nuevo con Pesca y Vida Silvestre de Florida (FWC, por sus siglas en inglés) en los Condados de Bahía y Golfo y Franklin. A pesar de los retos que suponen las lluvias, la escorrentía de las aguas pluviales y la baja salinidad, nuestros voluntarios de Scallop Sitter han proporcionado información valiosa a los investigadores y a los esfuerzos de restauración, especialmente en estos primeros años de nuestro programa. Los “Scallop Sitters” recogen información útil sobre la salinidad en las bahías de destino. Pero la mayor parte del impacto se produce al observar de cerca sus vieiras. Las vieiras que mantienen sus cuidadores tienen más posibilidades de desovar con éxito cuando sea el momento adecuado.
Una jaula “Scallop Sitter” lista para ser colocada cerca de las praderas marinas. Las jaulas son herramientas de restauración utilizadas para producir crías de vieira durante el ciclo anual de crecimiento. Foto de L. Scott Jackson.
¿Qué hace un cuidador de vieiras? Los voluntarios dirigen jaulas de exclusión de depredadores de vieiras, que quedan colocadas en la bahía o junto a un muelle. Los “Scallop Sitters” (cuidador de vieiras) vigilan la tasa de mortalidad y recogen datos sobre la salinidad que ayudan a determinar los objetivos de restauración y el éxito en las zonas seleccionadas.
¡Está invitado! ¡Cómo convertirse un “Scallop Sitter” (cuidador de vieiras)!
Las fechas de entrenamiento para 2023 se anunciarán en breve. Por favor, envíenos un correo electrónico si está interesado en ser voluntario o en recibir información adicional. Chantille Gooding, Coordinadora de Recursos Costeros del Condado de la Bahía. c.gooding@ufl.edu
Una institución con igualdad de oportunidades. UF/IFAS Extension, Universidad de Florida, Instituto de Ciencias Alimentarias y Agrícolas, Andra Johnson, Decana de UF/IFAS Extension. Las copias individuales de las publicaciones de UF/IFAS Extension (excluyendo las publicaciones de 4-H y de los jóvenes) están disponibles gratuitamente para los residentes de Florida en las oficinas de UF/IFAS Extension del condado.
We used to find them here. I have heard stories of folks who could fill a 5-gallon bucket with them in about 30 minutes right by Morgan Park. An old shrimper told me that back in the day when shrimping in Santa Rosa Sound they often found scallops along the points. They would drop a grab and collect them for sale. This was when both commercial scallop harvest, and shrimping, were allowed in Santa Rosa Sound. Neither are today. There are numerous tales of large beds of scallops in Big Lagoon and scientific reports of their presence in both locations and in Little Sabine. I myself have found them at Naval Live Oaks, Shoreline Park, Big Sabine, and in Big Lagoon.
Bay scallops need turtle grass to survive. Photo: UF IFAS
But that was a long time ago. The reports suggest the decline began in the 1960s and today it is rare to find one. What happen is hard to say but most believe it began with a decline in water quality. A decrease in salinity and an increase in nutrients from stormwater runoff degraded the environment for both the scallops and the turtle seagrass they depend on. Overharvesting certainly played a role.
But they are not all gone. There is still turtle grass in our system and occasionally reports of scallops. They are trying to hang on. There have also been attempts to improve water quality by modifying how stormwater is discharged into our bay, though there is much more to do there. Each year Florida Sea Grant Agents at our local county extension offices provide volunteers an opportunity to survey our bay for both species. We have a program called “Eyes on Seagrass” where volunteers monitor sites with seagrass once a month from April through October. We partner with Dr. Jane Caffrey from the University of West Florida to assess this. We also hold our annual “Pensacola Bay Scallop Search” each July.
In the Scallop Search volunteers will snorkel four different 50-meter transects lines either in Santa Rosa Sound or Big Lagoon searching for scallops. These surveys are conducted at the end of July. There are 11 survey grids in Big Lagoon and 55 in Santa Rosa Sound extending from Gulf Breeze to Navarre. To volunteer you will need a team of at least three people and your own snorkel gear. Some locations do require a boat to access. If you are interested in searching along the north shore of Santa Rosa Sound contact Chris Verlinde at chrismv@ufl.edu (850-623-3868). If you are interested in searching along the south shore of Santa Rosa Sound, or Big Lagoon, contact Rick O’Connor at roc1@ufl.edu (850-475-5230).
Volunteers conducting the great scallop search. Photo: Molly O’Connor
Reminder, harvesting scallops in Escambia and Santa Rosa counties is still illegal. Please give them a chance to recover.
The University of Florida/IFAS Extension faculty are reintroducing their acclaimed “Panhandle Outdoors LIVE!” series. Conservation lands and aquatic systems have vulnerabilities and face future threats to their ecological integrity. Come learn about the important role of these ecosystems.
The St. Joseph Bay and Buffer Preserve Ecosystems are home to some of the one richest concentrations of flora and fauna along the Northern Gulf Coast. This area supports an amazing diversity of fish, aquatic invertebrates, turtles, salt marshes and pine flatwoods uplands.
This one-day educational adventure is based at the St. Joseph Bay State Buffer Preserve near the coastal town of Port. St. Joe, Florida. It includes field tours of the unique coastal uplands and shoreline as well as presentations by area Extension Agents.
Details:
Registration fee is $45.
Meals: breakfast, lunch, drinks & snacks provided (you may bring your own)
Attire: outdoor wear, water shoes, bug spray and sun screen
*if afternoon rain is in forecast, outdoor activities may be switched to the morning schedule
Space is limited! Register now! See below.
Tentative schedule:
All Times Eastern
8:00 – 8:30 am Welcome! Breakfast & Overview with Ray Bodrey, Gulf County Extension
8:30 – 9:35 am Diamondback Terrapin Ecology, with Rick O’Connor, Escambia County Extension
9:35 – 9:45 am Q&A
9:45- 10:20 am The Bay Scallop & Habitat, with Ray Bodrey, Gulf County Extension
10:20 – 10:30 am Q&A
10:30 – 10:45 am Break
10:45 – 11:20 am The Hard Structures: Artificial Reefs & Marine Debris, with Scott Jackson, Bay County Extension
11:20 – 11:30 am Q&A
11:30 – 12:05 am The Apalachicola Oyster, Then, Now and What’s Next, with Erik Lovestrand, Franklin County Extension
12:05 – 12:15 pm Q&A
12:15 – 1:00 pm Lunch
1:00 – 2:30 pm Tram Tour of the Buffer Preserve (St. Joseph Bay State Buffer Preserve Staff)
2:30 – 2:40 pm Break
2:40 – 3:20 pm A Walk Among the Black Mangroves (All Extension Agents)
3:20 – 3:30 pm Wrap Up
To attend, you must register for the event at this site:
