Linking Java JNI application: _JNI_CreatedJavaVMs unresolved

I am migrating a Java JNI application from Linux (where it works under JDK1.6) to MacOSX 10.5.6 with JDK1.5. The link step fails:
reticuli:ims/ARC/java wmtaylor% ./compileIMSGUI.csh
Undefined symbols:
"_JNI_GetCreatedJavaVMs", referenced from:
ims5_1_monitor_nomain(int, char**)in ims5_1_monitor_nomain.o
"_main", referenced from:
start in crt1.10.5.o
ld: symbol(s) not found
collect2: ld returned 1 exit status

The compile script follows: ($JAVA_HOME = /usr)

$JAVA_HOME/bin/javac -Xlint -sourcepath $IMS_HOME/src -classpath $IMS_HOME/classes:$IMS_HOME/lib/plot.jar:$IMS_HOME/lib/Jama-1.0.2.jar -d $IMS_HOME/classes src/gov/nasa/arc/ims/gui/*.java src/gov/nasa/arc/ims/utils/*.java src/gov/nasa/arc/ims/commandLine/*.java

#

1. JNI processing

$JAVA_HOME/bin/javah -jni -classpath $IMS_HOME/classes -o ../cpp/src/ims5.1/RunMonitor.h gov.nasa.arc.ims.gui.RunMonitor

1. create .so library file

if (`uname` == "Linux") then

gcc -c -g -fPIC -Wno-deprecated -o $IMS_HOME/../cpp/src/ims5.1/ims5_1_monitor_jni.o $IMS_HOME/../cpp/src/ims5.1/ims5_1_monitor_jni.cpp -I $JAVA_HOME/include -I $JAVA_HOME/include/linux

gcc -fPIC -Wno-deprecated -c -o $IMS_HOME/../cpp/src/ims5.1/ims5_1_monitor_nomain.o $IMS_HOME/../cpp/src/ims5.1/ims5_1_monitor_nomain.cpp -I $JAVA_HOME/include -I $JAVA_HOME/include/linux

else
gcc -c -g -fPIC -Wno-deprecated -o $IMS_HOME/../cpp/src/ims5.1/ims5_1_monitor_jni.o $IMS_HOME/../cpp/src/ims5.1/ims5_1_monitor_jni.cpp -I /System/Library/Frameworks/JavaVM.framework/Versions/1.5.0/Headers

gcc -fPIC -Wno-deprecated -c -o $IMS_HOME/../cpp/src/ims5.1/ims5_1_monitor_nomain.o $IMS_HOME/../cpp/src/ims5.1/ims5_1_monitor_nomain.cpp -I /System/Library/Frameworks/JavaVM.framework/Versions/1.5.0/Headers
endif

gcc -shared -o $IMS_HOME/../cpp/src/ims5.1/libims5_1_monitor_jni.so $IMS_HOME/../cpp/src/ims5.1/ims5_1_monitor_jni.o $IMS_HOME/../cpp/src/ims5.1/ims5_1_monitor_nomain.o -lm -lstdc++ Thanks for any assistance,
Wm