Abstract/Details

Life history movements and spawning of São Francisco River fishes, Brazil


2005 2005

Other formats: Order a copy

Abstract (summary)

The São Francisco River (SFR), a floodplain river southeast of the Amazon River, provides commercial and recreational fishing for thousands of people, but fisheries have collapsed in the last decade. During 32-months, I radio-tracked 37 curimbatas (Prochilodus argenteus , Characidae, 0.8–2.9 kg) and 24 surubims (Pseudoplatystoma corruscans, Pimelodidae, 9.5–29.0 kg), two important commercial and recreational fishes. I did the study to characterize their migratory style and to determine if the cool hypolimnetic discharge from an upstream dam (Três Marias Reservoir, TMR) would block their upriver migration. I also made a conceptual model of the biological; river, dam, reservoir, and economic factors for a supplemental water release (SWR) to enhance SFR fisheries using a release from TMR. Migratory style of both species was dualistic with resident and migratory individuals. Home range was 1–127 km for curimbatá and 1–210 km for surubim. The most important spawning area for curimbatas was the SFR mainstem at its juncture with the Abaeté River mouth, and for surubims, the most important spawning area was the mainstem at Pirapora Rapids. Pre-spawning adults of both species staged at or near the spawning grounds. Some curimbatas and surubims homed to pre-spawning staging areas and to spawning areas. Some curimbatás also homed to non-spawning areas. The movements and thermal fluctuations experienced by both fishes showed they are eurythermal with a broad short-term temperature variation tolerance. Also, water discharged from dams that is <5°C cooler than ambient river water will not disrupt their migrations. The best date for a SRW is when there is a natural flood, which triggers spawning. The SWR will intensify the natural flood, cover a greater floodplain area, and increase survival of early life stages of fish. The TMR frequently impounded enough water for SWR only in the second half of the fish spawning season (January–March). Lost revenue at TMR depended on release volume and ranged from US$ 0.493 million to US$ 3.452 million for the actual power rate. However, SWR could increase commercial fisheries income an estimated US$ 4.468 million. Planned construction of 16 dams in the mainstem and tributaries downstream from TMD will greatly affect curimbatá and surubim migrations and spawning habitat, extirpate populations, and eventually reduce their abundance.

Indexing (details)


Subject
Aquaculture;
Fish production;
Ecology
Classification
0792: Aquaculture
0792: Fish production
0329: Ecology
Identifier / keyword
Biological sciences; Brazil; Fishes; Sao Francisco River; Spawning
Title
Life history movements and spawning of São Francisco River fishes, Brazil
Author
Godinho, Alexandre Lima
Number of pages
164
Publication year
2005
Degree date
2005
School code
0118
Source
DAI-B 66/06, Dissertation Abstracts International
Place of publication
Ann Arbor
Country of publication
United States
ISBN
9780542197604, 054219760X
Advisor
Kynard, Boyd
University/institution
University of Massachusetts Amherst
University location
United States -- Massachusetts
Degree
Ph.D.
Source type
Dissertations & Theses
Language
English
Document type
Dissertation/Thesis
Dissertation/thesis number
3179874
ProQuest document ID
304998128
Copyright
Database copyright ProQuest LLC; ProQuest does not claim copyright in the individual underlying works.
Document URL
http://search.proquest.com/docview/304998128
Access the complete full text

You can get the full text of this document if it is part of your institution's ProQuest subscription.

Try one of the following:

  • Connect to ProQuest through your library network and search for the document from there.
  • Request the document from your library.
  • Go to the ProQuest login page and enter a ProQuest or My Research username / password.