The Presence and Distribution of Sturgeon in the Damariscotta River Estuary
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The Presence and Distribution of Sturgeon in the Damariscotta River Estuary Kimberly Picard Gayle Zydlewski
description
The Presence and Distribution of Sturgeon in the Damariscotta River Estuary. Kimberly Picard Gayle Zydlewski. Goal. Document contemporary presence and distribution of tagged sturgeon in the Damariscotta River Estuary. Objectives. Locate habitat areas used by tagged sturgeon and - PowerPoint PPT Presentation
Transcript of The Presence and Distribution of Sturgeon in the Damariscotta River Estuary
The Presence and Distribution of Sturgeon in the
Damariscotta River EstuaryKimberly PicardGayle Zydlewski
Goal• Document contemporary presence and distribution of
tagged sturgeon in the Damariscotta River Estuary
Objectives• Locate habitat areas used by tagged sturgeon and
• Associate habitat use to:
• Abiotic features (e.g., temperature, salinity, depth)
• Biotic features (prey availability)
Photo courtesy: South Carolina DNR
Atlantic Vs. Shortnose sturgeon
Background• Both sturgeon species’ have been documented in
the Gulf of Maine– Kennebec River (Squiers and Smith 1979;
Wippelhauser et al., unpublished)– Penobscot River Estuary and Bay (Fernandes 2008).
– These tagged sturgeon moved to other river systems– Presence and distribution are influenced by suitable
environmental conditions, foraging and prey availability
Photo Courtesy: Cornell University Photo Courtesy: Cornell University
Tara Trinko, NOAA
SNS documented in multiple rivers…Zydlewski et al. 2011.
2006 - 2010 #of unique SNS
detectedPenobscot River 41
(25 emigrants)
Medomak River 5Damariscotta River
7
St. George River 11Kennebec River 24
Methods- Sturgeon in the Damariscotta
• Acoustic telemetry – Receivers record acoustic signals
from individual tags implanted in sturgeon
• Three stationary receivers placed in the river from Apr 12-Dec 5, 2012
• Weekly mobile surveys at 10 different locations from Sept 11-Nov 14, 2012
Photo courtesy: Zydlewski Lab
Methods- Environment• Weekly surveys
– Sep 11-Nov 14, 2012• At each of 10 locations:• Depth (m)• Surface and bottom temperature (°C)• Salinity (ppt)• Dissolved oxygen (mg/l)
• A PONAR grab was used to collect– Substrate – Benthic prey
Photo Courtesy: Matthew Dzaugis
Approximate locations of collected data of each trip (circles) and of three stationary receivers (stars).
DMC
Results- Passive receiversSturgeon movements in Damariscotta River estuary observed in 2012
‘D’ represents a fish detected on downstream receiver‘U’ represents fish detected on upstream receiver
Results- Environmental data
1 2 3 4 5 6 7 8 9 108
10
12
14
16
18
20
Location
Tem
pera
ture
(C)
1 2 3 4 5 6 7 8 9 108
10
12
14
16
18
20 9/11/2012
9/18/2012
9/26/2012
10/2/2012
10/17/2012
10/24/2012
10/31/2012
11/6/2012
11/14/2012
LocationTe
mpe
ratu
re (C
)Upstream Downstream
Warmer: Sept 11- Oct 2 Warmer: Sept 11- Oct 2
Colder: Oct 17- Nov 14 Colder: Oct 17- Nov 14
Upstream Downstream
Bottom water temperature Surface water temperature
Upstream
Downstream
Average depth (m) and salinity (ppt) at each survey location.
Results- Prey Availability
Before and After the 3°C temperature drop in October and upstream versus downstream.
Prey Species
Capitellidae sp.
Juvenile bivalve
Conclusions• Higher number of sturgeon in the spring
– related to warmer water conditions or prey diversity.
• Atlantic sturgeon only visited in the spring– may prefer warm water in small coastal rivers
• Sturgeon that stayed for >24hrs travelled further upriver, into shallower depths and warmer temperatures
– Perhaps to find additional food sources.
ConclusionsData suggest that:
Prey diversity and richness is higher upstream • perhaps a motivation for
sturgeon to move upstream
More prey were available in the summer than fall • perhaps a reason we see
more sturgeon in the Damariscotta in the spring.
National Marine Fisheries Service
Questions?
