Spatial dependence of calanoid copepod diversity in the North Atlantic Ocean

G Beaugrand,F Ibañez

doi:10.3354/meps232197

Abstract

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 232:197-211 (2002) - doi:10.3354/meps232197 Spatial dependence of calanoid copepod diversity in the North Atlantic Ocean Grégory Beaugrand1,*, Frédéric Ibañez2 1Sir Alister Hardy Foundation for Ocean Science, The Laboratory, Citadel Hill, Plymouth PL1 2PB, United Kingdom 2Observatoire Océanologique, Laboratoire d¹Océanologie Biologique et écologie du Plancton Marin, ESA 7076, BP 28, 06230, Villefranche sur mer, France *E-mail: gbea@mail.pml.ac.uk ABSTRACT: Ecosystems are fundamentally structured in space and time. The identification and quantification of scales of variability has occupied a central place in ecology for several decades. This paper examines spatial changes in the diversity of calanoid copepods and its regional dependence in the North Atlantic Ocean at diel, seasonal and interannual scales. Point cumulative semi-variograms, initially proposed for geological purposes, are described and intensively used to understand the relationships between diversity and its spatial scales of variability. A map of the mean spatial dependence in calanoid diversity is then proposed and diel and seasonal changes examined. This shows that diversity changes at small spatial scales over the European shelf seas. In oceanic areas, diversity changes at large spatial scales in both the subarctic and the northern boundary of the subtropical gyres. Low spatial scales of variability are detected in the Gulf Stream extension, in the path of the North Atlantic Current and west of Europe. A negative relationship between diversity and its spatial dependence is found in almost all the oceanic regions. This relationship is constant at all temporal scales. At an annual scale, relationships between diversity, spatial dependence and climatic indices have been investigated. Some links have been detected but both the intensity and the sign of these relationships vary greatly in space. The regime shift that took place in the North Sea after 1988 involved a sharp change in the diversity of calanoid copepods and a significant strengthening in the contrast between the neritic and oceanic spatial dependence. KEY WORDS: Spatial scale of variability · Point cumulative semi-variograms · Calanoid copepods · Pelagic diversity · Continuous Plankton Recorder (CPR) survey Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 232. Online publication date: May 03, 2002 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2002 Inter-Research.

Highlights

Planque (1996) used experimental semi-variograms to examine the spatial scale of variability of Calanus finmarchicus and C. helgolandicus for different months across the North Atlantic Ocean
In order to illustrate Sen’s point cumulative semi-variogram (PCSV) model, data were firstly selected in the North Atlantic Ocean from 1960 to 1980 for August, using only night data (Fig. 2a)
The regional experimental semi-variogram (Fig. 2b) calculated from these data shows that the diversity of calanoid copepods is spatially dependent up until about 1200 km where the semi-variogram levelled off

Summary

Introduction

Ecosystems are fundamentally structured in space and time (Margalef 1979, Frontier & Pichot-Viale 1993, Lundberg et al 2000), and the identification and the quantification of scales of variability has been a topic of great importance in ecology for several decades (e.g. Levin 1992, Mann & Lazier 1996, Haury & McGowan 1998, Beaugrand et al 2001). Haury et al (1978), by the use of a 3-dimensional time-space plot (Stommel 1963), estimated the spatial and temporal structure of zooplankton biomass variability. Haury et al (1978), by the use of a 3-dimensional time-space plot (Stommel 1963), estimated the spatial and temporal structure of zooplankton biomass variability. One-dimensional spectral analysis has been applied to examine spatial scales of variability of. Mar Ecol Prog Ser 232: 197–211, 2002 biological variables such as chlorophyll fluorescence and copepod abundance (Tsuda et al 1993) or physical variables (Yoder et al 1993). Semi-variograms, proposed for the first time by Matheron (1962), are often applied to identify spatial behaviour of a biological variable at different spatial scales Planque (1996) used experimental semi-variograms to examine the spatial scale of variability of Calanus finmarchicus and C. helgolandicus for different months across the North Atlantic Ocean

Methods

Results

Conclusion