function [t,f,a,n,lon,lat,depth] = bio_read_oa4(ctdfile,chlfile,nh4file,no3file)

%-----------------------------------------------------------------------------
% Read BIO and GRID variables
%-----------------------------------------------------------------------------

ncload(ctdfile,'temp'), t = temp; clear temp   % Temperature
ncload(chlfile,'salt'), f = salt; clear salt   % Fluorescence 
ncload(nh4file,'temp'), a = temp; clear temp   % Ammonium
ncload(no3file,'salt'), n = salt; clear salt   % Nitrate

ncload(ctdfile, 'grid3')
lon = grid3(:,:,1);
lat = grid3(:,:,2);

ncload(ctdfile, 'zout')
depth = -zout(:,3);

return

