Residence time and habitat duration for 
predators in a small mid-Atlantic estuary 
Email address for the contact author: john.manderson@noaa.gov 
Abstract— Residence times of individ- 
ual fishes should reflect the durations 
over which habitat resources support 
survival, metabolic maintenance, and 
adequate growth. From May to Octo- 
ber in 2006 and 2007, we measured 
residencies of ultrasonically tagged 
age-la- Striped Bass ( Morone saxati- 
lis ; n= 46), age-0 and age-l+ Bluefish 
(. Pomatomus saltatrix\ n = 45 and 35) 
and age-l+ Weakfish (Cynoscion rega- 
lis ; w=41) in a small estuarine tribu- 
tary in New Jersey with 32 ultrasonic 
receivers to monitor movements and 
sensors to measure habitat resources. 
Striped Bass and age-l+ Bluefish used 
the estuary for medians of 9.5 days 
(d) (max=58 d) and 22 d (max=88 d), 
and age-0 Bluefish and Weakfish were 
resident for medians of 30 d (max=52 
d) and 41 d (max=88 d), respectively 
Small individuals <500 mm TL were 
likely to remain in the estuary longer 
at warmer temperatures than were 
large individuals. Size-dependent 
temperature responses were similar 
to optimal temperatures for growth 
reported in previous studies. Freshwa- 
ter discharge also influenced residence 
time. All species were likely to remain 
in the estuary until freshwater dis- 
charge rates fell to a value associated 
with the transition of the estuarine 
state from a partially to fully mixed 
state. This transition weakens flows 
into the upstream salt front where 
prey concentrations usually are high. 
Time of estuarine residence appeared 
to be regulated by temperatures that 
controlled scopes for growth and the 
indirect effects of freshwater discharge 
on prey productivity and concentration. 
Changes in the seasonal phenology of 
temperature, precipitation, and human 
water use could alter the durations 
over which small estuarine tributar- 
ies serve as suitable habitats. 
Manuscript submitted 5 April 2013. 
Manuscript accepted 10 March 2014. 
Fish. Bull. 112:144-158 (2014). 
doi:10.7755/FB.112.2-3.4 
The views and opinions expressed or 
implied in this article are those of the 
author (or authors) and do not necessarily 
reflect the position of the National 
Marine Fisheries Service, NOAA. 
John P. Manderson (contact author) 
Linda L. Stehlik 
Jeff Pessutti 
John Rosendale 
Beth Phelan 
Behavioral Ecology Branch 
Northeast Fisheries Science Center 
National Marine Fisheries Service, NOAA 
James J. Howard Marine Sciences Laboratory 
74 Magruder Road 
Highlands, New Jersey 07732 
Temperate estuaries serve as spawn- 
ing, nursery, and feeding habitats for 
many fishes and invertebrates dur- 
ing warmer months (Mann, 2000; 
Able, 2005; Able and Fahay, 2010). 
Warm temperatures, high nutrient- 
stimulated primary and secondary 
productivity, and abundant spatial 
or structural refuges from preda- 
tion enhance growth and survival. 
However, because estuaries are shal- 
low, semi-enclosed bodies of water 
along the land-sea boundary, high- 
frequency atmospheric variability is 
rapidly translated into variability in 
biophysical processes that regulate 
the vital rates of species (e.g., water 
temperature, freshwater discharge, 
nutrient inputs, circulation and re- 
tention, and dissolved oxygen). Estu- 
arine habitat suitability is, therefore, 
largely controlled by atmospheric 
and tidal forcing. As a result, estua- 
rine habitat suitability is dynamic, 
and suitable habitats have temporal 
dimensions of timing and duration 
that are as important as the spatial 
dimensions of location and volume 
(Livingston, 1987; Manderson et ah, 
2002; Manderson et ah, 2003; Man- 
derson et ah, 2006; Peterson et al., 
2007). 
Animals move in variable envi- 
ronments to fulfill requirements for 
survival, metabolic maintenance, 
growth, and reproduction and are 
believed to “climb” local fitness gra- 
dients that fall within their percep- 
tual ranges (Armsworth and Rough- 
garden, 2005). Individual animals 
should minimize movement costs by 
becoming resident in suitable habi- 
tats until more costly long-distance 
movements are required by changes 
in habitat resources, such as tem- 
perature, oxygen concentrations, and 
concentrations of predators or prey 
or by life history event schedules. 
Changes in atmospheric forcing (e.g., 
air temperature and precipitation) 
that change both the timing and per- 
sistence of suitable shallow coastal 
habitats should affect the movement 
costs and energy budgets of the in- 
dividual animals that use them. Be- 
cause changes in atmospheric forcing 
and hydrography are coherent over 
spatial scales of 100s to 1000s of ki- 
lometers (Hare and Able, 2007; Man- 
derson, 2008; Shearman and Lentz, 
2010), effects on energy budgets of 
individual animals are likely to af- 
fect demographic rates at the popu- 
lation level. 
In this study, we used passive ul- 
trasonic biotelemetry and environ- 
mental monitoring to measure rela- 
tionships of residence and egress of 
3 predators — Striped Bass (age-l+ 
Morone saxatilis), Bluefish (age-0 
