Brian F. Beal Professor of Marine Ecology University of Maine at Machias.
-
Upload
clarence-crawford -
Category
Documents
-
view
216 -
download
0
description
Transcript of Brian F. Beal Professor of Marine Ecology University of Maine at Machias.
![Page 1: Brian F. Beal Professor of Marine Ecology University of Maine at Machias.](https://reader036.fdocuments.in/reader036/viewer/2022081517/5a4d1b837f8b9ab0599bbd07/html5/thumbnails/1.jpg)
![Page 2: Brian F. Beal Professor of Marine Ecology University of Maine at Machias.](https://reader036.fdocuments.in/reader036/viewer/2022081517/5a4d1b837f8b9ab0599bbd07/html5/thumbnails/2.jpg)
Brian F. Beal
Professor of Marine Ecology
University of Maine at Machias
![Page 3: Brian F. Beal Professor of Marine Ecology University of Maine at Machias.](https://reader036.fdocuments.in/reader036/viewer/2022081517/5a4d1b837f8b9ab0599bbd07/html5/thumbnails/3.jpg)
Assessing re-seeding efforts
![Page 4: Brian F. Beal Professor of Marine Ecology University of Maine at Machias.](https://reader036.fdocuments.in/reader036/viewer/2022081517/5a4d1b837f8b9ab0599bbd07/html5/thumbnails/4.jpg)
Sea scallop restoration, or enhancement, efforts come in all shapes and sizes
III. Spawner sanctuaries
II. Transplanting hatchery- reared individuals
I. Spat collectors
![Page 5: Brian F. Beal Professor of Marine Ecology University of Maine at Machias.](https://reader036.fdocuments.in/reader036/viewer/2022081517/5a4d1b837f8b9ab0599bbd07/html5/thumbnails/5.jpg)
How does one assess project success?
Scale
Large Small
![Page 6: Brian F. Beal Professor of Marine Ecology University of Maine at Machias.](https://reader036.fdocuments.in/reader036/viewer/2022081517/5a4d1b837f8b9ab0599bbd07/html5/thumbnails/6.jpg)
![Page 7: Brian F. Beal Professor of Marine Ecology University of Maine at Machias.](https://reader036.fdocuments.in/reader036/viewer/2022081517/5a4d1b837f8b9ab0599bbd07/html5/thumbnails/7.jpg)
Mea
n G
onad
Inde
x
0
5
10
15
20
Jan Feb Mar Apr May Jun JunMay Jul Jul Aug Aug Sep SepOct Nov Dec
Mea
n G
onad
Inde
x
0
5
10
15
20
Jan Feb Mar Apr May Jun JunMay Jul Jul Aug Aug Sep SepOct Nov Dec
Females
Males
In eastern Maine, scallops begin to spawn in mid- late August and continue through mid-September
![Page 8: Brian F. Beal Professor of Marine Ecology University of Maine at Machias.](https://reader036.fdocuments.in/reader036/viewer/2022081517/5a4d1b837f8b9ab0599bbd07/html5/thumbnails/8.jpg)
![Page 9: Brian F. Beal Professor of Marine Ecology University of Maine at Machias.](https://reader036.fdocuments.in/reader036/viewer/2022081517/5a4d1b837f8b9ab0599bbd07/html5/thumbnails/9.jpg)
![Page 10: Brian F. Beal Professor of Marine Ecology University of Maine at Machias.](https://reader036.fdocuments.in/reader036/viewer/2022081517/5a4d1b837f8b9ab0599bbd07/html5/thumbnails/10.jpg)
![Page 11: Brian F. Beal Professor of Marine Ecology University of Maine at Machias.](https://reader036.fdocuments.in/reader036/viewer/2022081517/5a4d1b837f8b9ab0599bbd07/html5/thumbnails/11.jpg)
Scenario I: Transplanting sea scallop seed
Designing a restoration effort with analysis in mind
a. Identify those factors that contribute to scallop mortality?
Transplant siteTransplant site
Transplant time of yearTransplant time of year
Stocking densityStocking density
Initial scallop sizeInitial scallop size
Predator type, size, abundancePredator type, size, abundance
![Page 12: Brian F. Beal Professor of Marine Ecology University of Maine at Machias.](https://reader036.fdocuments.in/reader036/viewer/2022081517/5a4d1b837f8b9ab0599bbd07/html5/thumbnails/12.jpg)
Time
Mea
n P
erce
nt S
urvi
val
SurvivalGrowth
Mea
n S
hell
Leng
th
commercial size
time to reach commercial size
Determine how important each potential source of mortality is using survival and growth as dependent variables
![Page 13: Brian F. Beal Professor of Marine Ecology University of Maine at Machias.](https://reader036.fdocuments.in/reader036/viewer/2022081517/5a4d1b837f8b9ab0599bbd07/html5/thumbnails/13.jpg)
Transplant site
How representativerepresentative is the site you have chosen with respect to the suite of other
potential transplant sites in terms of:
Food
Habitat
Hydrogrophy
How do you know?
![Page 14: Brian F. Beal Professor of Marine Ecology University of Maine at Machias.](https://reader036.fdocuments.in/reader036/viewer/2022081517/5a4d1b837f8b9ab0599bbd07/html5/thumbnails/14.jpg)
Transplant time of year
To date, most sea scallops juveniles have been seeded in the spring at very small sizes
WHY? Because, this is the time of year…
1. that maximizes both growth and survival?
2. that is convenient?
3. when predators are not as voracious?
4. when sea scallops naturally settle and begin to grow?
Are these answers
accurate?
![Page 15: Brian F. Beal Professor of Marine Ecology University of Maine at Machias.](https://reader036.fdocuments.in/reader036/viewer/2022081517/5a4d1b837f8b9ab0599bbd07/html5/thumbnails/15.jpg)
Stocking density and transplant size
What stocking density and transplant size optimizes growth to commercial size?
Is this: site specific? size-specific?
Do these parameters change from one year to the next?
How do you know?
![Page 16: Brian F. Beal Professor of Marine Ecology University of Maine at Machias.](https://reader036.fdocuments.in/reader036/viewer/2022081517/5a4d1b837f8b9ab0599bbd07/html5/thumbnails/16.jpg)
Predators
What predators attack what size seed?
When is predation heaviest?
Is it possible to reduce predator effective-ness or deter predation?
Can predators be trapped?
Are predators important?
How do you know?
![Page 17: Brian F. Beal Professor of Marine Ecology University of Maine at Machias.](https://reader036.fdocuments.in/reader036/viewer/2022081517/5a4d1b837f8b9ab0599bbd07/html5/thumbnails/17.jpg)
A larger question ?
Designing a restoration effort with analysis in mind?
How do we know that wild collection is the How do we know that wild collection is the most effective method to obtain large most effective method to obtain large
numbers of sea scallop juveniles?numbers of sea scallop juveniles?
![Page 18: Brian F. Beal Professor of Marine Ecology University of Maine at Machias.](https://reader036.fdocuments.in/reader036/viewer/2022081517/5a4d1b837f8b9ab0599bbd07/html5/thumbnails/18.jpg)
The Three Levels of Assessing Efficacy of Stock Enhancement Programs
1.“We seeded, so it was successful!”
2. Monitoring regularly or intermittently through time to follow the fate (growth/ survival) of a subset of seeded individuals.
3. Monitoring combined with determining the actual mechanisms (sources of mortality) and their overall importance.
![Page 19: Brian F. Beal Professor of Marine Ecology University of Maine at Machias.](https://reader036.fdocuments.in/reader036/viewer/2022081517/5a4d1b837f8b9ab0599bbd07/html5/thumbnails/19.jpg)
Transplant Site
You have some boundary you must stay within
![Page 20: Brian F. Beal Professor of Marine Ecology University of Maine at Machias.](https://reader036.fdocuments.in/reader036/viewer/2022081517/5a4d1b837f8b9ab0599bbd07/html5/thumbnails/20.jpg)
Transplant Site
Enhancement
Site0.25
km
0.50 km
![Page 21: Brian F. Beal Professor of Marine Ecology University of Maine at Machias.](https://reader036.fdocuments.in/reader036/viewer/2022081517/5a4d1b837f8b9ab0599bbd07/html5/thumbnails/21.jpg)
Multiple transplant sites
Representative
![Page 22: Brian F. Beal Professor of Marine Ecology University of Maine at Machias.](https://reader036.fdocuments.in/reader036/viewer/2022081517/5a4d1b837f8b9ab0599bbd07/html5/thumbnails/22.jpg)
![Page 23: Brian F. Beal Professor of Marine Ecology University of Maine at Machias.](https://reader036.fdocuments.in/reader036/viewer/2022081517/5a4d1b837f8b9ab0599bbd07/html5/thumbnails/23.jpg)
Manipulative Experiment to test effects of….
Stocking density
Seed size
Predator exclusion
Predator inclusion
(Shell damage)
![Page 24: Brian F. Beal Professor of Marine Ecology University of Maine at Machias.](https://reader036.fdocuments.in/reader036/viewer/2022081517/5a4d1b837f8b9ab0599bbd07/html5/thumbnails/24.jpg)
Transplant time of year
Shell Length (mm)
Per
cent
Sur
viva
l
Small Large
Low
Hig
h
Per
cent
of Y
early
Gro
wth
0
10
20
30
40
50
60
![Page 25: Brian F. Beal Professor of Marine Ecology University of Maine at Machias.](https://reader036.fdocuments.in/reader036/viewer/2022081517/5a4d1b837f8b9ab0599bbd07/html5/thumbnails/25.jpg)
Possible Future Directions
![Page 26: Brian F. Beal Professor of Marine Ecology University of Maine at Machias.](https://reader036.fdocuments.in/reader036/viewer/2022081517/5a4d1b837f8b9ab0599bbd07/html5/thumbnails/26.jpg)
Emphasis should be placed on assessing the best method of collecting the most wild sea
scallops possible in terms of site, deployment times, water depth, materials used, amount of
time collectors spend in the water, and the cost per effort to collect 1,000 individuals of size X
AND/OR
Developing husbandry methods to spawn adults, and to rear larvae and juveniles to a transplantable size, and assess the cost per effort to produce 1,000 individuals of size X
![Page 27: Brian F. Beal Professor of Marine Ecology University of Maine at Machias.](https://reader036.fdocuments.in/reader036/viewer/2022081517/5a4d1b837f8b9ab0599bbd07/html5/thumbnails/27.jpg)
Only when we have determined the best method of collecting or producing sea
scallops – that is, a method that is repeatable, predictable, and you can take to
the bank, can we begin to assess the efficacy of our enhancement efforts.
But, once we have made that determination
…………
![Page 28: Brian F. Beal Professor of Marine Ecology University of Maine at Machias.](https://reader036.fdocuments.in/reader036/viewer/2022081517/5a4d1b837f8b9ab0599bbd07/html5/thumbnails/28.jpg)
We need to admit that here in Maine, we are not sophisticated in our understanding of how to enhance wild sea scallop stocks to know
even if the scallops we collect at present actually live and grow to commercial size
![Page 29: Brian F. Beal Professor of Marine Ecology University of Maine at Machias.](https://reader036.fdocuments.in/reader036/viewer/2022081517/5a4d1b837f8b9ab0599bbd07/html5/thumbnails/29.jpg)
Where do we begin?We ask funders to invest in an applied research project
that involves fishermen and scientists to look at a combination of factors that we know influence sea scallop survival and growth. These studies should
examine how well scallop juveniles do when seeded at different sizes, times of year, and bottom sites. The studies should be designed to assess the fate and
growth of individuals over a long enough time frame to allow the development of site-index curves
Time
Mea
n P
erce
nt S
urvi
val
SurvivalGrowth
Mea
n S
hell
Leng
th
commercial size
time to reach commercial size
Site-index curve
![Page 30: Brian F. Beal Professor of Marine Ecology University of Maine at Machias.](https://reader036.fdocuments.in/reader036/viewer/2022081517/5a4d1b837f8b9ab0599bbd07/html5/thumbnails/30.jpg)
So, we must begin to …….. LEARNLEARN
By devising thoughtful, well-planned seeding trials (where the fate of individuals is followed through time) using different size scallops planted at various “representative sites” at various times of the year Thanks!