diff --git a/testing_and_setup/compass/ocean/global_ocean/config_files/config_culled_mesh.xml b/testing_and_setup/compass/ocean/global_ocean/config_files/config_culled_mesh.xml
index 1661abb424..06f2242e92 100644
--- a/testing_and_setup/compass/ocean/global_ocean/config_files/config_culled_mesh.xml
+++ b/testing_and_setup/compass/ocean/global_ocean/config_files/config_culled_mesh.xml
@@ -9,6 +9,7 @@
 	<add_link source_path="script_configuration_dir" source="cull_mesh.py" dest="cull_mesh.py"/>
 	<add_link source_path="mpas_tools" source="ocean/coastline_alteration/add_land_locked_cells_to_mask.py" dest="add_land_locked_cells_to_mask.py"/>
 	<add_link source_path="mpas_tools" source="ocean/coastline_alteration/widen_transect_edge_masks.py" dest="widen_transect_edge_masks.py"/>
+	<add_link source_path="mpas_tools" source="ocean/coastline_alteration/add_critical_land_blockages_to_mask.py" dest="add_critical_land_blockages_to_mask.py"/>
 
 	<run_script name="run.py">
 		<step executable="./cull_mesh.py">
diff --git a/testing_and_setup/compass/ocean/global_ocean/cull_mesh.py b/testing_and_setup/compass/ocean/global_ocean/cull_mesh.py
index 224d3fb567..48065e7310 100755
--- a/testing_and_setup/compass/ocean/global_ocean/cull_mesh.py
+++ b/testing_and_setup/compass/ocean/global_ocean/cull_mesh.py
@@ -22,6 +22,10 @@
 The optional --with_critical_passages flag indicates that critical
 passages are to be opened. Otherwise, steps 2, 5 and 9 are skipped
 """
+
+from __future__ import absolute_import, division, print_function, \
+    unicode_literals
+
 import os
 import os.path
 import subprocess
@@ -58,7 +62,8 @@ def removeFile(fileName):
         '-f', landCoverage,
         '-m', landCoverageMask,
         '-o', 'land_coverage.geojson']
-print "running", ' '.join(args)
+print("running {}".format(' '.join(args)))
+
 subprocess.check_call(args, env=os.environ.copy())
 
 # Add the appropriate land coverage below 60S (either all ice or grounded ice).
@@ -71,9 +76,11 @@ def removeFile(fileName):
 
 args = ['{}/merge_features.py'.format(path), '-f', antarcticLandCoverage,
         '-o', 'land_coverage.geojson']
-print "running", ' '.join(args)
+print("running {}".format(' '.join(args)))
+
 subprocess.check_call(args, env=os.environ.copy())
 
+
 # Create the land mask based on the land coverage, i.e. coastline data.
 # Run command is:
 # ./MpasMaskCreator.x  base_mesh.nc land_mask.nc -f land_coverage.geojson
@@ -81,19 +88,25 @@ def removeFile(fileName):
     './MpasMaskCreator.x',
     'base_mesh.nc',
     'land_mask_1_from_land_coverage.nc',
-    '-f',
-    'land_coverage.geojson']
-print "running", ' '.join(args)
+    '-f', 'land_coverage.geojson']
+print("running {}".format(' '.join(args)))
+
 subprocess.check_call(args, env=os.environ.copy())
 
+if options.with_critical_passages:
+    outMaskFile = 'land_mask_2_from_land_locked_cells.nc'
+else:
+    outMaskFile = 'land_mask_final.nc'
+
 # Add land-locked cells to land coverage mask.
 args = ['./add_land_locked_cells_to_mask.py',
         '-f', 'land_mask_1_from_land_coverage.nc',
-        '-o', 'land_mask_final.nc',
+        '-o', outMaskFile,
         '-m', 'base_mesh.nc',
         '-l', '43.0',
         '-n', '20']
-print "running", ' '.join(args)
+print("running {}".format(' '.join(args)))
+
 subprocess.check_call(args, env=os.environ.copy())
 
 # create seed points for a flood fill of the ocean
@@ -104,7 +117,8 @@ def removeFile(fileName):
         '-d', '{}/ocean/point'.format(path),
         '-t', 'seed_point',
         '-o', 'seed_points.geojson']
-print "running", ' '.join(args)
+print("running {}".format(' '.join(args)))
+
 subprocess.check_call(args, env=os.environ.copy())
 
 if options.with_critical_passages:
@@ -114,7 +128,8 @@ def removeFile(fileName):
             '-d', '{}/ocean/transect'.format(path),
             '-t', 'Critical_Passage',
             '-o', 'critical_passages.geojson']
-    print "running", ' '.join(args)
+    print("running {}".format(' '.join(args)))
+
     subprocess.check_call(args, env=os.environ.copy())
 
     # create masks from the transects
@@ -123,7 +138,8 @@ def removeFile(fileName):
     # -f critical_passages.geojson
     args = ['./MpasMaskCreator.x', 'base_mesh.nc', 'critical_passages_mask.nc',
             '-f', 'critical_passages.geojson']
-    print "running", ' '.join(args)
+    print("running {}".format(' '.join(args)))
+
     subprocess.check_call(args, env=os.environ.copy())
 
     # Alter critical passages to be at least two cells wide, to avoid sea ice
@@ -132,7 +148,36 @@ def removeFile(fileName):
             '-f', 'critical_passages_mask.nc',
             '-m', 'base_mesh.nc',
             '-l', '43.0']
-    print "running", ' '.join(args)
+    print("running {}".format(' '.join(args)))
+
+    subprocess.check_call(args, env=os.environ.copy())
+
+    # merge transects for critical land blockages into
+    # critical_land_blockages.geojson
+    removeFile('critical_land_blockages.geojson')
+    args = ['{}/merge_features.py'.format(path),
+            '-d', '{}/ocean/transect'.format(path),
+            '-t', 'Critical_Land_Blockage',
+            '-o', 'critical_land_blockages.geojson']
+    print("running {}".format(' '.join(args)))
+
+    subprocess.check_call(args, env=os.environ.copy())
+
+    # create masks from the transects for critical land blockages
+    args = ['./MpasMaskCreator.x', 'base_mesh.nc',
+            'critical_land_blockages_mask.nc',
+            '-f', 'critical_land_blockages.geojson']
+    print("running {}".format(' '.join(args)))
+
+    subprocess.check_call(args, env=os.environ.copy())
+
+    # add critical land blockages to land_mask_final.nc
+    args = ['./add_critical_land_blockages_to_mask.py',
+            '-f', 'land_mask_2_from_land_locked_cells.nc',
+            '-o', 'land_mask_final.nc',
+            '-b', 'critical_land_blockages_mask.nc']
+    print("running {}".format(' '.join(args)))
+
     subprocess.check_call(args, env=os.environ.copy())
 
     # Cull the mesh based on the land mask while keeping critical passages open
@@ -141,7 +186,8 @@ def removeFile(fileName):
     # -p critical_passages_mask.nc
     args = ['./MpasCellCuller.x', 'base_mesh.nc', 'culled_mesh_preliminary.nc',
             '-m', 'land_mask_final.nc', '-p', 'critical_passages_mask.nc']
-    print "running", ' '.join(args)
+    print("running {}".format(' '.join(args)))
+
     subprocess.check_call(args, env=os.environ.copy())
 else:
 
@@ -150,7 +196,8 @@ def removeFile(fileName):
     # ./MpasCellCuller.x  base_mesh.nc culled_mesh_preliminary.nc -m land_mask_final.nc
     args = ['./MpasCellCuller.x', 'base_mesh.nc', 'culled_mesh_preliminary.nc',
             '-m', 'land_mask_final.nc']
-    print "running", ' '.join(args)
+    print("running {}".format(' '.join(args)))
+
     subprocess.check_call(args, env=os.environ.copy())
 
 # create a mask for the flood fill seed points
@@ -158,7 +205,8 @@ def removeFile(fileName):
 # ./MpasMaskCreator.x  culled_mesh_preliminary.nc seed_mask.nc -s seed_points.geojson
 args = ['./MpasMaskCreator.x', 'culled_mesh_preliminary.nc', 'seed_mask.nc',
         '-s', 'seed_points.geojson']
-print "running", ' '.join(args)
+print("running {}".format(' '.join(args)))
+
 subprocess.check_call(args, env=os.environ.copy())
 
 
@@ -168,7 +216,8 @@ def removeFile(fileName):
 args = ['./MpasCellCuller.x', 'culled_mesh_preliminary.nc', 'culled_mesh.nc',
         '-i', 'seed_mask.nc']
 
-print "running", ' '.join(args)
+print("running {}".format(' '.join(args)))
+
 subprocess.check_call(args, env=os.environ.copy())
 
 if options.with_critical_passages:
@@ -179,5 +228,6 @@ def removeFile(fileName):
     args = ['./MpasMaskCreator.x', 'culled_mesh.nc',
             'critical_passages_mask_final.nc',
             '-f', 'critical_passages.geojson']
-    print "running", ' '.join(args)
+    print("running {}".format(' '.join(args)))
+
     subprocess.check_call(args, env=os.environ.copy())